<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Folgosa, F</style></author><author><style face="normal" font="default" size="100%">Timoteo, C. G.</style></author><author><style face="normal" font="default" size="100%">Guilherme, M.</style></author><author><style face="normal" font="default" size="100%">Penas, D.</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Bacterioferritin from Desulfovibrio vulgaris Hildenborough is a functional DPS-like enzyme</style></title><secondary-title><style face="normal" font="default" size="100%">Febs Journal</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000308128602518</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">279</style></volume><pages><style face="normal" font="default" size="100%">465-465</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">n/a</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 0 Folgosa, F. Timoteo, C. G. Guilherme, M. Penas, D. Tavares, P. Pereira, A. S. 22nd IUBMB Congress/37th FEBS Congress SEP 04-09, 2012 Seville, SPAIN IUBMB, FEBS 1 SI&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Timoteo, C. G.</style></author><author><style face="normal" font="default" size="100%">Guilherme, M.</style></author><author><style face="normal" font="default" size="100%">Penas, D.</style></author><author><style face="normal" font="default" size="100%">Folgosa, F</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Desulfovibrio vulgaris bacterioferritin uses H2O2 as a co-substrate for iron oxidation and reveals DPS-like DNA protection and binding activities</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemical Journal</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000307626300012</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">446</style></volume><pages><style face="normal" font="default" size="100%">125-133</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;A gene encoding Bfr (bacterioferritin) was identified and isolated from the genome of Desulfovibrio vulgaris cells, and overexpressed in Escherichia coli. In vitro, H2O2 oxidizes Fe2+ ions at much higher reaction rates than O-2. The H2O2 oxidation of two Fe2+ ions was proven by Mossbauer spectroscopy of rapid freeze-quenched samples. On the basis of the Mossbauer parameters of the intermediate species we propose that D. vulgaris Bfr follows a mineralization mechanism similar to the one reported for vertebrate H-type ferritins subunits, in which a diferrous centre at the ferroxidase site is oxidized to diferric intermediate species, that are subsequently translocated into the inner nanocavity. D. vulgaris recombinant Bfr oxidizes and stores up to 600 iron atoms per protein. This Bfr is able to bind DNA and protect it against hydroxyl radical and DNase deleterious effects. The use of H2O2 as an oxidant, combined with the DNA binding and protection activities, seems to indicate a DPS (DNA-binding protein from starved cells)-like role for D. vulgaris Bfr.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 0 Timoteo, Cristina G. Guilherme, Marcia Penas, Daniela Folgosa, Filipe Tavares, Pedro Pereira, Alice S. Part 1&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Timoteo, C. G.</style></author><author><style face="normal" font="default" size="100%">Guilherme, M.</style></author><author><style face="normal" font="default" size="100%">Folgosa, F</style></author><author><style face="normal" font="default" size="100%">Naik, S. G.</style></author><author><style face="normal" font="default" size="100%">Duarte, A. G.</style></author><author><style face="normal" font="default" size="100%">HUYNH, BH</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Spectroscopic Evidence for and Characterization of a Trinuclear Ferroxidase Center in Bacterial Ferritin from Desulfovibrio vulgaris Hildenborough</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of the American Chemical Society</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000305863900028</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">26</style></number><volume><style face="normal" font="default" size="100%">134</style></volume><pages><style face="normal" font="default" size="100%">10822-10832</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Ferritins are ubiquitous and can be found in practically all organisms that utilize Fe. They are composed of 24 subunits forming a hollow sphere with an inner cavity of similar to 80 angstrom in diameter. The main function of ferritin is to oxidize the cytotoxic Fe2+ ions and store the oxidized Fe in the inner cavity. It has been established that the initial step of rapid oxidation of Fe2+ (ferroxidation) by H-type ferritins, found in vertebrates, occurs at a diiron binding center, termed the ferroxidase center. In bacterial ferritins, however, X-ray crystallographic evidence and amino acid sequence analysis revealed a trinuclear Fe binding center comprising a binuclear Fe binding center (sites A and B), homologous to the ferroxidase center of H-type ferritin, and an adjacent mononuclear Fe binding site (site C). In an effort to obtain further evidence supporting the presence of a trinuclear Fe binding center in bacterial ferritins and to gain information on the states of the iron bound to the trinuclear center, bacterial ferritin from Desulfovibrio vulgaris (DvFtn) and its E130A variant was loaded with substoichiometric amounts of Fe2+, and the products were characterized by Mossbauer and EPR spectroscopy. Four distinct Fe species were identified: a paramagnetic diferrous species, a diamagnetic diferrous species, a mixed valence Fe2+Fe3+ species, and a mononuclear Fe2+ species. The latter three species were detected in the wild-type DvFtn, while the paramagnetic diferrous species was detected in the E130A variant. These observations can be rationally explained by the presence of a trinuclear Fe binding center, and the four Fe species can be properly assigned to the three Fe binding sites. Further, our spectroscopic data suggest that (1) the fully occupied trinuclear center supports an all ferrous state, (2) sites B and C are bridged by a mu-OH group forming a diiron subcenter within the trinuclear center, and (3) this subcenter can afford both a mixed valence Fe2+Fe3+ state and a diferrous state. Mechanistic insights provided by these new findings are discussed and a minimal mechanistic scheme involving O-O bond cleavage is proposed.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 0 Pereira, Alice S. Timoteo, Cristina G. Guilherme, Marcia Folgosa, Filipe Naik, Sunil G. Duarte, Americo G. Boi Hanh Huynh Tavares, Pedro&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Siopa, F.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Ferreira, LM</style></author><author><style face="normal" font="default" size="100%">Marques, M. M.</style></author><author><style face="normal" font="default" size="100%">Branco, P.S.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Synthesis of catecholamine conjugates with nitrogen-centered bionucleophiles</style></title><secondary-title><style face="normal" font="default" size="100%">Bioorganic Chemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000313902300003</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">44</style></volume><pages><style face="normal" font="default" size="100%">19-24</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The enzymatic (tyrosinase) and chemical (NaIO4, Ag2O or Fremys's salt) oxidation of biologically relevant catecholamines, such as dopamine (DA), N-acetyldopamine (NADA) and the Ecstasy metabolites (alpha-MeDA and N-Me-alpha-MeDA) generates the corresponding o-quinone which can be trapped with nitrogen bionucleophiles such as N-acetyl-histidine and imidazole in a regioselective reaction that takes place predominantly at the 6-position of the catecholamine. (C) 2012 Elsevier Inc. All rights reserved.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 0 Siopa, Filipa Pereira, Alice S. Ferreira, Luisa M. Matilde Marques, M. Branco, Paula S.&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Cordas, C. M.</style></author><author><style face="normal" font="default" size="100%">Wilton, J.</style></author><author><style face="normal" font="default" size="100%">Cardoso, T.</style></author><author><style face="normal" font="default" size="100%">Folgosa, F</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Electrochemical behaviour of Dps-a mini-ferritin</style></title><secondary-title><style face="normal" font="default" size="100%">European Biophysics Journal with Biophysics Letters</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000293637300489</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">40</style></volume><pages><style face="normal" font="default" size="100%">181-181</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">n/a</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 0 Cordas, Cristina M. Wilton, Joana Cardoso, Tania Folgosa, Filipe Pereira, Alice S. Tavares, Pedro 8th EBSA European Biophysics Congress AUG 23-27, 2011 Budapest, HUNGARY Hungarian Biophys Soc, European Biophys Soc Assoc 1&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Timoteo, C. G.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Martins, C. E.</style></author><author><style face="normal" font="default" size="100%">Naik, S. G.</style></author><author><style face="normal" font="default" size="100%">Duarte, A. G.</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">HUYNH, BH</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Low-Spin Heme b(3) in the Catalytic Center of Nitric Oxide Reductase from Pseudomonas nautica</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000290594000004</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">20</style></number><volume><style face="normal" font="default" size="100%">50</style></volume><pages><style face="normal" font="default" size="100%">4251-4262</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Respiratory nitric oxide reductase (NOR) was purified from membrane extract of Pseudomonas (Ps.) nautica cells to homogeneity as judged by polyacrylamide gel electrophoresis. The purified protein is a heterodimer with subunits of molecular masses of 54 and 18 kDa. The gene encoding both subunits was cloned and sequenced. The amino acid sequence shows strong homology with enzymes of the cNOR class. Iron/heme determinations show that one heme c is present in the small subunit (NORC) and that approximately two heme b and one non-heme iron are associated with the large subunit (NORB), in agreement with the available data for enzymes of the cNOR class. Mossbauer characterization of the as-purified, ascorbate-reduced, and dithionite-reduced enzyme confirms the presence of three heme groups (the catalytic heme b(3) and the electron transfer heme b and heme c) and one redox-active non-heme Fe (Fe-B). Consistent with results obtained for other cNORs, heme c and heme b in Ps. nautica cNOR were found to be low-spin while FeB was found to be high-spin. Unexpectedly, as opposed to the presumed high-spin state for heme b(3), the Mossbauer data demonstrate unambiguously that heme b(3) is, in fact, low-spin in both ferric and ferrous states, suggesting that heme b(3) is six-coordinated regardless of its oxidation state. EPR spectroscopic measurements of the as-purified enzyme show resonances at the g similar to 6 and g similar to 2-3 regions very similar to those reported previously for other cNORs. The signals at g = 3.60, 2.99, 2.26, and 1.43 are attributed to the two charge-transfer low-spin ferric heme c and heme b. Previously, resonances at the g similar to 6 region were assigned to a small quantity of uncoupled high-spin Fe-III heme b(3). This assignment is now questionable because heme b(3) is low-spin. On the basis of our spectroscopic data, we argue that the g = 6.34 signal is likely arising from a spin spin coupled binuclear center comprising the low-spin Fe-III heme b(3) and the high-spin Fe-B(III). Activity assays performed under various reducing conditions indicate that heme b(3) has to be reduced for the enzyme to be active. But, from an energetic point of view, the formation of a ferrous heme-NO as an initial reaction intermediate for NO reduction is disfavored because heme [FeNO](7) is a stable product. We suspect that the presence of a sixth ligand in the Fe-II-heme b(3) may weaken its affinity for NO and thus promotes, in the first catalytic step, binding of NO at the Fe-B(II) site. The function of heme b(3) would then be to orient the Fe-B-bound NO molecules for the formation of the N-N bond and to provide reducing equivalents for NO reduction.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 4 Timoteo, Cristina G. Pereira, Alice S. Martins, Carlos E. Naik, Sunil G. Duarte, Americo G. Moura, Jose J. G. Tavares, Pedro Huynh, Boi Hanh Moura, Isabel&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Folgosa, F</style></author><author><style face="normal" font="default" size="100%">Cordas, C. M.</style></author><author><style face="normal" font="default" size="100%">Santos, J. A.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">New spectroscopic and electrochemical insights on a class I superoxide reductase: evidence for an intramolecular electron-transfer pathway</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemical Journal</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000295182100010</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">438</style></volume><pages><style face="normal" font="default" size="100%">485-494</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;SORs (superoxide reductases) are enzymes involved in bacterial resistance to reactive oxygen species, catalysing the reduction of superoxide anions to hydrogen peroxide. So far three structural classes have been identified. Class I enzymes have two ironcentre-containing domains. Most studies have focused on the catalytic iron site (centre II), yet the role of centre I is poorly understood. The possible roles of this iron site were approached by an integrated study using both classical and fast kinetic measurements, as well as direct electrochemistry. A new heterometallic form of the protein with a zinc-substituted centre I, maintaining the iron active-site centre II, was obtained, resulting in a stable derivative useful for comparison with the native all-iron from. Second-order rate constants for the electron transfer between reduced rubredoxin and the different SOR forms were determined to be 2.8 x 10(7) M(-1) . s(-1) and 1.3 x 10(6) M(-1) . s(-1) for SOR(Fe(IIII)-Fe(II)) and for SOR(Fe(IIII)-Fe(III)) forms respectively, and 3.2 x 10(6) M(-1) s(-1) for the SOR(Zn(II)-Fe(III)) form. The results obtained seem to indicate that centre I transfers electrons from the putative physiological donor rubredoxin to the catalytic active iron site (intramolecular process). In addition, electrochemical results show that conformational changes are associated with the redox state of centre I, which may enable a faster catalytic response towards superoxide anion. The apparent rate constants calculated for the SOR-mediated electron transfer also support this observation.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 2 Folgosa, Filipe Cordas, Cristina M. Santos, Joana A. Pereira, Alice S. Moura, Jose J. G. Tavares, Pedro Moura, Isabel Part 3&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Ferreira, I.M.P.L.V.O.</style></author><author><style face="normal" font="default" size="100%">Pinho, O.</style></author><author><style face="normal" font="default" size="100%">Monteiro, D.</style></author><author><style face="normal" font="default" size="100%">Faria, S.</style></author><author><style face="normal" font="default" size="100%">Cruz, S.</style></author><author><style face="normal" font="default" size="100%">Perreira, A</style></author><author><style face="normal" font="default" size="100%">Roque, A. C.</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Short communication: Effect of kefir grains on proteolysis of major milk proteins</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Dairy Science</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2010</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000272966100004</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">1</style></number><volume><style face="normal" font="default" size="100%">93</style></volume><pages><style face="normal" font="default" size="100%">27-31</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The effect of kefir grains on the proteolysis of major milk proteins in milk kefir and in a culture of kefir grains in pasteurized cheese whey was followed by reverse phase-HPLC analysis. The reduction of kappa-, alpha-, and beta-caseins (CN), alpha-lactalbumin (alpha-LA), and beta-lactoglobulin (beta-LG) contents during 48 and 90 h of incubation of pasteurized milk (100 mL) and respective cheese whey with kefir grains (6 and 12 g) at 20 degrees C was monitored. Significant proteolysis of alpha-LA and kappa-, alpha-, and beta-caseins was observed. The effect of kefir amount (6 and 12 g/100 mL) was significant for alpha-LA and alpha- and beta-CN. alpha-Lactalbumin and beta-CN were more easily hydrolyzed than alpha-CN. No significant reduction was observed with respect to beta-LG concentration for 6 and 12 g of kefir in 100 mL of milk over 48 h, indicating that no significant proteolysis was carried out. Similar results were observed when the experiment was conducted over 90 h. Regarding the cheese whey kefir samples, similar behavior was observed for the proteolysis of alpha-LA and beta-LG: alpha-LA was hydrolyzed between 60 and 90% after 12 h (for 6 and 12 g of kefir) and no significant beta-LG proteolysis occurred. The proteolytic activity of lactic acid bacteria and yeasts in kefir community was evaluated. Kefir milk prepared under normal conditions contained peptides from proteolysis of alpha-LA and kappa-, alpha-, and beta-caseins. Hydrolysis is dependent on the kefir: milk ratio and incubation time. beta-Lactoglobulin is not hydrolyzed even when higher hydrolysis time is used. Kefir grains are not appropriate as adjunct cultures to increase beta-LG digestibility in whey-based or whey-containing foods.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 3 Ferreira, I. M. P. L. V. O. Pinho, O. Monteiro, D. Faria, S. Cruz, S. Perreira, A. Roque, A. C. Tavares, P.&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Conrath, K.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Martins, C. E.</style></author><author><style face="normal" font="default" size="100%">Timoteo, C. G.</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Spinelli, S.</style></author><author><style face="normal" font="default" size="100%">Kinne, J.</style></author><author><style face="normal" font="default" size="100%">Flaudrops, C.</style></author><author><style face="normal" font="default" size="100%">Cambillau, C</style></author><author><style face="normal" font="default" size="100%">Muyldermans, S.</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Tegoni, M</style></author><author><style face="normal" font="default" size="100%">Desmyter, A.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Camelid nanobodies raised against an integral membrane enzyme, nitric oxide reductase</style></title><secondary-title><style face="normal" font="default" size="100%">Protein Science</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000264941700013</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">3</style></number><volume><style face="normal" font="default" size="100%">18</style></volume><pages><style face="normal" font="default" size="100%">619-628</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Nitric Oxide Reductase (NOR) is an integral membrane protein performing the reduction of NO to N(2)O. NOR is composed of two subunits: the large one (NorB) is a bundle of 12 transmembrane helices (TMH). It contains a b type heme and a binuclear iron site, which is believed to be the catalytic site, comprising a heme b and a non-hemic iron. The small subunit (NorC) harbors a cytochrome c and is attached to the membrane through a unique TMH. With the aim to perform structural and functional studies of NOR, we have immunized dromedaries with NOR and produced several antibody fragments of the heavy chain (VHHs, also known as nanobodies (TM)). These fragments have been used to develop a faster NOR purification procedure, to proceed to crystallization assays and to analyze the electron transfer of electron donors. BIAcore experiments have revealed that up to three VHHs can bind concomitantly to NOR with affinities in the nanomolar range. This is the first example of the use of VHHs with an integral membrane protein. Our results indicate that VHHs are able to recognize with high affinity distinct epitopes on this class of proteins, and can be used as versatile and valuable tool for purification, functional study and crystallization of integral membrane proteins.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 11 Conrath, Katja Pereira, Alice S. Martins, Carlos E. Timoteo, Cristina G. Tavares, Pedro Spinelli, Silvia Kinne, Joerg Flaudrops, Christophe Cambillau, Christian Muyldermans, Serge Moura, Isabel Moura, Jose J. G. Tegoni, Mariella Desmyter, Aline&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Rivas, M. G.</style></author><author><style face="normal" font="default" size="100%">Mota, C. S.</style></author><author><style face="normal" font="default" size="100%">Pauleta, S. R.</style></author><author><style face="normal" font="default" size="100%">Carepo, M. S. P.</style></author><author><style face="normal" font="default" size="100%">Folgosa, F</style></author><author><style face="normal" font="default" size="100%">Andrade, S. L. A.</style></author><author><style face="normal" font="default" size="100%">Fauque, G</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Calvete, JJ</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Isolation and characterization of a new Cu-Fe protein from Desulfovibrio aminophilus DSM12254</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Inorganic Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000270795900004</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">10</style></number><volume><style face="normal" font="default" size="100%">103</style></volume><pages><style face="normal" font="default" size="100%">1314-1322</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The isolation and characterization of a new metalloprotein containing Cu and Fe atoms is reported. The as-isolated Cu-Fe protein shows an UV-visible spectrum with absorption bands at 320 nm, 409 nm and 615 nm. Molecular mass of the native protein along with denaturating electrophoresis and mass spectrometry data show that this protein is a multimer consisting of 14 +/- 1 subunits of 15254.3 +/- 7.6 Da. Mossbauer spectroscopy data of the as-isolated Cu-Fe protein is consistent with the presence of [2Fe-2S](2+) centers. Data interpretation of the dithionite reduced protein suggest that the metallic cluster could be constituted by two ferromagnetically coupled [2Fe-2S](+) spin delocalized pairs. The biochemical properties of the Cu-Fe protein are similar to the recently reported molybdenum resistance associated protein from Desulfovibrio, D. alaskensis. Further-more, a BLAST search from the DNA deduced amino acid sequence shows that the Cu-Fe protein has homology with proteins annotated as zinc resistance associated proteins from Desulfovibrio, D. alaskensis, D. vulgaris Hildenborough, D. piger ATCC 29098. These facts suggest a possible role of the Cu-Fe protein in metal tolerance. (C) 2009 Published by Elsevier Inc.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 1 Rivas, Maria G. Mota, Cristiano S. Pauleta, Sofia R. Carepo, Marta S. P. Folgosa, Filipe Andrade, Susana L. A. Fauque, Guy Pereira, Alice S. Tavares, Pedro Calvete, Juan J. Moura, Isabel Moura, Jose J. G. 1st Latin American Meeting on Biological Inorganic Chemistry (LABIC2008) AUG 31-SEP 04, 2008 Iguazu Falls, BRAZIL SI&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Rivas, M. G.</style></author><author><style face="normal" font="default" size="100%">Carepo, M. S. P.</style></author><author><style face="normal" font="default" size="100%">Mota, C. S.</style></author><author><style face="normal" font="default" size="100%">Korbas, M.</style></author><author><style face="normal" font="default" size="100%">Durand, M. C.</style></author><author><style face="normal" font="default" size="100%">Lopes, A. T.</style></author><author><style face="normal" font="default" size="100%">Brondino, CD</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">George, GN</style></author><author><style face="normal" font="default" size="100%">Dolla, A.</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Molybdenum Induces the Expression of a Protein Containing a New Heterometallic Mo-Fe Cluster in Desulfovibrio alaskensis</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000263047900009</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">5</style></number><volume><style face="normal" font="default" size="100%">48</style></volume><pages><style face="normal" font="default" size="100%">873-882</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The characterization of a novel Mo-Fe protein (MorP) associated with a system that responds to Mo in Desulfovibrio alaskensis is reported. Biochemical characterization shows that MorP is a periplasmic homomultimer of high molecular weight (260 +/- 13 kDa) consisting of 16-18 monomers of 15321.1 +/- 0.5 Da. The UV/visible absorption spectrum of the as-isolated protein shows absorption peaks around 280, 320, and 570 nm with extinction coefficients of 18700, 12800, and 5000 M(-1) cm(-1), respectively. Metal content, EXAFS data and DFT calculations support the presence of a Mo-2S-[2Fe-2S]-2S-Mo cluster never reported before. Analysis of the available genomes from Desulfovibrio species shows that the MorP encoding gene is located downstream of a sensor and a regulator gene. This type of gene arrangement, called two component system, is used by the cell to regulate diverse physiological processes in response to changes in environmemtal conditions. Increase of both gene expression and protein production was observed when cells were cultured in the presence of 45 mu M molybdenum. Involvement of this system in Mo tolerance of sulfate reducing bacteria is proposed.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 8 Rivas, Maria G. Carepo, Marta S. P. Mota, Cristiano S. Korbas, Malgorzata Durand, Marie-Claire Lopes, Ana T. Brondino, Carlos D. Pereira, Alice S. George, Graham N. Dolla, Alain Moura, Jose J. G. Moura, Isabel&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Dell'acqua, S.</style></author><author><style face="normal" font="default" size="100%">Pauleta, S. R.</style></author><author><style face="normal" font="default" size="100%">Monzani, E</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Casella, L.</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Electron transfer complex between nitrous oxide reductase and cytochrome c(552) from Pseudomonas nautica: Kinetic, nuclear magnetic resonance, and docking studies</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000259868300004</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">41</style></number><volume><style face="normal" font="default" size="100%">47</style></volume><pages><style face="normal" font="default" size="100%">10852-10862</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The multicopper enzyme nitrous oxide reductase (N2OR) catalyzes the final step of denitrification, the two-electron reduction of N2O to N-2. This enzyme is a functional homodimer containing two different multicopper sites: CuA and CuZ. CuA is a binuclear copper site that transfers electrons to the tetranuclear copper sulfide CuZ, the catalytic site. In this study, Pseudomonas nautica cytochrome C-552 was identified as the physiological electron donor. The kinetic data show differences when physiological and artificial electron donors are compared [cytochrome vs methylviologen (MV)]. In the presence of cytochrome c(552), the reaction rate is dependent on the ET reaction and independent of the N2O concentration. With MV, electron donation is faster than substrate reduction. From the study of cytochrome c(552) concentration dependence, we estimate the following kinetic parameters: K-mc512 = 50.2 +/- 9.0 mu M and V-maxc551 1.8 +/- 10.6 units/mg. The N2O concentration dependence indicates a K-mN2O of 14.0 +/- 2.9 mu M using MV as the electron donor. The pH effect on the kinetic parameters is different when MV or cytochrome c(552) is used as the electron donor (pK(a) = 6.6 or 8.3, respectively). The kinetic study also revealed the hydrophobic nature of the interaction, and direct electron transfer studies showed that CuA is the center that receives electrons from the physiological electron donor. The formation of the electron transfer complex was observed by H-1 NMR protein-protein titrations and was modeled with a molecular docking program (BiGGER). The proposed docked complexes corroborated the ET studies giving a large number of solutions in which cytochrome c(552) is placed near a hydrophobic patch located around the CuA center.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 9 Dell'Acqua, Simone Pauleta, Sofia R. Monzani, Enrico Pereira, Alice S. Casella, Luigi Moura, Jose J. G. Moura, Isabel&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Gavel, OY</style></author><author><style face="normal" font="default" size="100%">Bursakov, SA</style></author><author><style face="normal" font="default" size="100%">Di Rocco, G</style></author><author><style face="normal" font="default" size="100%">Trincao, J</style></author><author><style face="normal" font="default" size="100%">Pickering, I. J.</style></author><author><style face="normal" font="default" size="100%">George, GN</style></author><author><style face="normal" font="default" size="100%">Calvete, JJ</style></author><author><style face="normal" font="default" size="100%">Shnyrov, VL</style></author><author><style face="normal" font="default" size="100%">Brondino, CD</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Lampreia, J</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A new type of metal-binding site in cobalt- and zinc-containing adenylate kinases isolated from sulfate-reducers Desulfovibrio gigas and Desulfovibrio desulfuricans ATCC 27774</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Inorganic Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000256239600042</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">5-6</style></number><volume><style face="normal" font="default" size="100%">102</style></volume><pages><style face="normal" font="default" size="100%">1380-1395</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Adenylate kinase (AK) mediates the reversible transfer of phosphate groups between the adenylate nucleotides and contributes to the maintenance of their constant cellular level, necessary for energy metabolism and nucleic acid synthesis. The AK were purified from crude extracts of two sulfate-reducing bacteria (SRB), Desulfovibrio (D.) gigas NCIB 9332 and Desulfovibrio desulfuricans ATCC 27774, and biochemically and spectroscopically characterised in the native and fully cobalt- or zinc-substituted forms. These are the first reported adenylate kinases that bind either zinc or cobalt and are related to the subgroup of metal-containing AK found, in most cases, in Gram-positive bacteria. The electronic absorption spectrum is consistent with tetrahedral coordinated cobalt, predominantly via sulfur ligands, and is supported by EPR. The involvement of three cysteines in cobalt or zinc coordination was confirmed by chemical methods. Extended X-ray absorption fine structure (EXAFS) indicate that cobalt or zinc are bound by three cysteine residues and one histidine in the metal-binding site of the &quot;LID&quot; domain. The sequence (129)Cys-X(5)-His-X(15)-Cys-X(2)-Cys of the AK from D. gigas is involved in metal coordination and represents a new type of binding motif that differs from other known zinc-binding sites of AK. Cobalt and zinc play a structural role in stabilizing the LID domain. (C) 2008 Elsevier Inc. All rights reserved.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 7 Gavel, Olga Yu. Bursakov, Sergey A. Di Rocco, Giulia Trincao, Jose Pickering, Ingrid J. George, Graham N. Calvete, Juan J. Shnyrov, Valery L. Brondino, Carlos D. Pereira, Alice S. Lampreia, Jorge Tavares, Pedro Moura, Jose J. G. Moura, Isabel 13th International Conference on Biological Inorganic Chemistry JUL 15-20, 2007 Vienna, AUSTRIA&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Fisher, K.</style></author><author><style face="normal" font="default" size="100%">Lowe, D. J.</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">HUYNH, BH</style></author><author><style face="normal" font="default" size="100%">Edmondson, D</style></author><author><style face="normal" font="default" size="100%">Newton, W. E.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Conformations generated during turnover of the Azotobacter vinelandii nitrogenase MoFe protein and their relationship to physiological function</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Inorganic Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000251523100014</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">11-12</style></number><volume><style face="normal" font="default" size="100%">101</style></volume><pages><style face="normal" font="default" size="100%">1649-1656</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Various S = 3/2 EPR signals elicited from wild-type and variant Azotobacter vinelandii nitrogenase MoFe proteins appear to reflect different conformations assumed by the FeMo-cofactor with different protonation states. To determine whether these presumed changes in protonation and conformation reflect catalytic capacity, the responses (particularly to changes in electron flux) of the alpha H195Q, alpha H195N, and alpha Q191 K variant MoFe proteins (where His at position 195 in the alpha subunit is replaced by Gln/Asn or Gln at position alpha-191 by Lys), which have strikingly different substrate-reduction properties, were studied by stopped-flow or rapid-freeze techniques. Rapid-freeze EPR at low electron flux (at 3-fold molar excess of wild-type Fe protein) elicited two transient FeMo-cofactor-based EPR signals within 1 s of initiating turnover under N-2 with the alpha H195Q and alpha H195N variants, but not with the alpha Q191K variant. No EPR signals attributable to P cluster oxidation were observed for any of the variants under these conditions. Furthermore, during turnover at low electron flux with the wild-type, alpha H195Q or alpha H195N MoFe protein, the longer-time 430-nm absorbance increase, which likely reflects P cluster oxidation, was also not observed (by stopped-flow spectrophotometry); it did, however, occur for all three MoFe proteins under higher electron flux. No 430-nm absorbance increase occurred with the alpha Q191K variant, not even at higher electron flux. This putative lack of involvement of the P cluster in electron transfer at low electron flux was confirmed by rapid-freeze Fe-57 Mossbauer spectroscopy, which clearly showed FeMo-factor reduction without P cluster oxidation. Because the wild-type, alpha H195Q and alpha H195N MoFe proteins can bind N-2, but alpha Q195K cannot, these results suggest that P cluster oxidation occurs only under high electron flux as required for N-2 reduction. (C) 2007 Elsevier Inc. All rights reserved.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 5 Fisher, Karl Lowe, David J. Tavares, Pedro Pereira, Alice S. Huynh, Boi Hanh Edmondson, Dale Newton, William E.&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Ferreira, I.M.P.L.V.O.</style></author><author><style face="normal" font="default" size="100%">Eca, R.</style></author><author><style face="normal" font="default" size="100%">Pinho, O.</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Pereira, A.</style></author><author><style face="normal" font="default" size="100%">Roque, A. C.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Development and validation of an HPLC/UV method for quantification of bioactive peptides in fermented milks</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Liquid Chromatography &amp; Related Technologies</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000248539300023</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">13-16</style></number><volume><style face="normal" font="default" size="100%">30</style></volume><pages><style face="normal" font="default" size="100%">2139-2147</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The simultaneous separation and quantification of two casein peptides (IPP, VPP) presenting potent inhibitory activity of angiotensin-converting-enzyme (ACE) and casein in fermented milks was developed. Gradient elution was carried out at a flow-rate of 1 mL/min, using a mixture of two solvents. Solvent A was 0.1% TFA in water and solvent B was acetonitrile-water-trifluoracetic acid 95:5:0.1. The effluent was monitored by UV detector at 214 nm. Calibration curves were constructed in the interval of 0.01-1.0 mg/mL for VPP, 0.005-1.0 mg/mL for IPP, and 0.05-3.0 mg/mL for casein. R 2 invariably exceeded 0.999. The detection limits were 0.004 for VPP, 0.002 mg/mL for IPP, and 0.02 mg/mL for casein. Repeatability of the method was evaluated by six consecutive injections of two standard solutions containing VPP, IPP, and casein. The RSD values for concentration were all below 5.08%. Recovery studies were carried out to determine the accuracy of the method. Recoveries ranged between 88 and 98.2%. The methodology was applied, not only, for the monitorization of VPP, IPP, and casein in commercial fermented milks labeled as presenting anti hypertensive properties, but also, in milk with different degrees of fermentation by L Helveticus, and in other commercial functional fermented milks, such as, those presenting cholesterol lowering properties.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 8 Ferreira, Isabel M. P. L. V. O. Eca, Rosario Pinho, Olivia Tavares, Pedro Pereira, Alice Roque, Ana Cecilia&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pauleta, S. R.</style></author><author><style face="normal" font="default" size="100%">Duarte, A. G.</style></author><author><style face="normal" font="default" size="100%">Carepo, M. S.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">NMR assignment of the apo-form of a Desulfovibrio gigas protein containing a novel Mo-Cu cluster</style></title><secondary-title><style face="normal" font="default" size="100%">Biomolecular Nmr Assignments</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000258686800025</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">1</style></number><volume><style face="normal" font="default" size="100%">1</style></volume><pages><style face="normal" font="default" size="100%">81-83</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;We report the 98% assignment of the apo-form of an orange protein, containing a novel Mo-Cu cluster isolated from Desulfovibrio gigas. This protein presents a region where backbone amide protons exchange fast with bulk solvent becoming undetectable. These residues were assigned using C-13-detection experiments.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 4 Pauleta, Sofia R. Duarte, Americo G. Carepo, Marta S. Pereira, Alice S. Tavares, Pedro Moura, Isabel Moura, Jose J. G.&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Ferreira, I.M.P.L.V.O.</style></author><author><style face="normal" font="default" size="100%">Pinho, O.</style></author><author><style face="normal" font="default" size="100%">Mota, M. V.</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Pereira, A.</style></author><author><style face="normal" font="default" size="100%">Goncalves, M. P.</style></author><author><style face="normal" font="default" size="100%">Torres, D.</style></author><author><style face="normal" font="default" size="100%">Rocha, C.</style></author><author><style face="normal" font="default" size="100%">Teixeira, J. A.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Preparation of ingredients containing an ACE-inhibitory peptide by tryptic hydrolysis of whey protein concentrates</style></title><secondary-title><style face="normal" font="default" size="100%">International Dairy Journal</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000244369300009</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">5</style></number><volume><style face="normal" font="default" size="100%">17</style></volume><pages><style face="normal" font="default" size="100%">481-487</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;This study describes the characterisation of whey protein hydrolysates obtained from tryptic hydrolysis to assess their application as ingredients with angiotensin-converting-enzyme (ACE) inhibitory action. The levels of a-lactalbumin (alpha-la) and P-lactoglobulin (beta-lg) remaining after hydrolysis were quantified. Peptides were separated by RP-HPLC, and Ala-Leu-Pro-Met-His-Ile-Arg (ALPMHIR), the most potent beta-lg-derived ACE-inhibitory peptide was monitored. A correlation curve was established for the production of this peptide as a function of hydrolysis time. Heat-induced gelation of hydrolysates was studied by small-deformation rheology. The gelation times and the strength of the final gels were highly dependent on the degree of hydrolysis. Smaller peptides liberated by hydrolysis contributed to the inability of whey protein hydrolysates to gel. (c) 2006 Elsevier Ltd. All rights reserved.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 20 Ferreira, I. M. P. L. V. O. Pinho, O. Mota, M. V. Tavares, P. Pereira, A. Goncalves, M. P. Torres, D. Rocha, C. Teixeira, J. A.&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Folgosa, F</style></author><author><style face="normal" font="default" size="100%">Almeida, R. M.</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Superoxide reductases</style></title><secondary-title><style face="normal" font="default" size="100%">European Journal of Inorganic Chemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000247937300008</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">18</style></number><pages><style face="normal" font="default" size="100%">2569-2581</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Reactive oxygen species (ROS), when in excess, are among the most deleterious species an organism can deal with. The physiological effects of ROS include amino acid chain cleavage, DNA degradation and lipid oxidation, among others. They can be formed in the cytoplasm in a variety of ways, including autooxidation reactions (FMN- and FAD-containing enzymes) and Fenton reactions as a result of the cytoplasmatic pool of iron ions. The superoxide anion (021, despite its short half-life in solution, is particularly pernicious as it can form other reactive ROS (such as the strong oxidant peroxynitrite) or oxidize and/or reduce cellular components. For strict anaerobic or microaerophilic bacteria it is of particular importance to be able to dispose of ROS in a controlled manner, especially if these organisms are temporarily exposed to air. This review aims to describe the structural characteristics of superoxide reductases (SORs) and mechanistic aspects of biological superoxide anion reduction. SORs can be considered the main class of enzymes behind the oxygen detoxification pathway of anaerobic and microaerophilic bacteria. The geometry of the active site (three classes have been described), the possible electron donors in vivo and the current hypothesis for the catalytic mechanism will be discussed. Some phylogenetic considerations are presented, regarding the primary structure of SORs currently available in genome databases. ((c) Wiley-VCH Verlag GmbH &amp;amp; Co. KGaA, 69451 Weinheim, Germany, 2007).&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 14 Pereira, Alice S. Tavares, Pedro Folgosa, Filipe Almeida, Rui M. Moura, Isabel Moura, Jose J. G.&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Metalloenzymes of the denitrification pathway</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Inorganic Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000242919600021</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">12</style></number><volume><style face="normal" font="default" size="100%">100</style></volume><pages><style face="normal" font="default" size="100%">2087-2100</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Denitrification, or dissimilative nitrate reduction, is an anaerobic process used by some bacteria for energy generation. This process is important in many aspects, but its environmental implications have been given particular relevance. Nitrate accumulation and release of nitrous oxide in the atmosphere due to excess use of fertilizers in agriculture are examples of two environmental problems where denitrification plays a central role. The reduction of nitrate to nitrogen gas is accomplished by four different types of metalloenzymes in four simple steps: nitrate is reduced to nitrite, then to nitric oxide, followed by the reduction to nitrous oxide and by a final reduction to dinitrogen. In this manuscript we present a concise updated review of the bioinorganic aspects of denitrification. (c) 2006 Elsevier Inc. All rights reserved.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 59 Tavares, P. Pereira, A. S. Moura, J. J. G. Moura, I.&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Cordas, C. M.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Martins, C. E.</style></author><author><style face="normal" font="default" size="100%">Timoteo, C. G.</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Nitric oxide reductase: Direct electrochemistry and electrocatalytic activity</style></title><secondary-title><style face="normal" font="default" size="100%">Chembiochem</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000242981500009</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">12</style></number><volume><style face="normal" font="default" size="100%">7</style></volume><pages><style face="normal" font="default" size="100%">1878-1881</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">n/a</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 3 Cordas, Cristina M. Pereira, Alice S. Martins, Carlos E. Timoteo, Cristina G. Moura, Isabel Moura, Jose J. G. Tavares, Pedro&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Bursakov, SA</style></author><author><style face="normal" font="default" size="100%">Gavel, OY</style></author><author><style face="normal" font="default" size="100%">Di Rocco, G</style></author><author><style face="normal" font="default" size="100%">Lampreia, J</style></author><author><style face="normal" font="default" size="100%">Calvete, J</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Antagonists Mo and Cu in a heterometallic cluster present on a novel protein (orange protein) isolated from Desulfovibrio gigas</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Inorganic Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2004</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000221678300020</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">5</style></number><volume><style face="normal" font="default" size="100%">98</style></volume><pages><style face="normal" font="default" size="100%">833-840</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;An orange-coloured protein (ORP) isolated from Desulfovibrio gigas, a sulphate reducer, has been previously shown by extended X-ray absorption fine structure (EXAFS) to contain a novel mixed-metal sulphide cluster of the type [S2MoS2CuS2MoS2] [J. Am. Chem. Soc. 122 (2000) 8321]. We report here the purification and the biochemical/spectroscopic characterisation of this novel protein. ORP is a soluble monomeric protein (11.8 kDa). The cluster is non-covalently bound to the polypeptide chain. The presence of a MoS42- moiety in the structure of the cofactor contributes with a quite characteristic UV-Vis spectra, exhibiting an orange colour, with intense absorption peaks at 480 and 338 nm. Pure ORP reveals an Abs(480)/Abs(338) ratio of 0.535. The gene sequence coding for ORP as well as the amino acid sequence was determined. The putative biological function of ORP is discussed. (C) 2003 Elsevier Inc. All rights reserved.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 14 Bursakov, SA Gavel, OY Di Rocco, G Lampreia, J Calvete, J Pereira, AS Moura, JJG Moura, I 11th International Conference on Biological Inorganic Chemistry JUL 19-23, 2003 Cairns, AUSTRALIA&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pauleta, Sr.</style></author><author><style face="normal" font="default" size="100%">Guerlesquin, F.</style></author><author><style face="normal" font="default" size="100%">Goodhew, C. F.</style></author><author><style face="normal" font="default" size="100%">Devreese, B</style></author><author><style face="normal" font="default" size="100%">VanBeeumen, J</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Pettigrew, G. W.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Paracoccus pantotrophus pseudoazurin is an electron donor to cytochrome c peroxidase</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2004</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000223708400008</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">35</style></number><volume><style face="normal" font="default" size="100%">43</style></volume><pages><style face="normal" font="default" size="100%">11214-11225</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The gene for pseudoazurin was isolated from Paracoccus pantotrophus LMD 52.44 and expressed in a heterologous system with a yield of 54.3 mg of pure protein per liter of culture. The gene and protein were shown to be identical to those from P. pantotrophus LMD 82.5. The extinction coefficient of the protein was re-evaluated and was found to be 3.00 mM(-1) cm(-1) at 590 nm. It was confirmed that the oxidized protein is in a weak monomer/dimer equilibrium that is ionic- strength-dependent. The pseudoazurin was shown to be a highly active electron donor to cytochrome c peroxidase, and activity showed an ionic strength dependence consistent with an electrostatic interaction. The pseudoazurin has a very large dipole moment, the vector of which is positioned at the putative electron-transfer site, His81, and is conserved in this position across a wide range of blue copper proteins. Binding of the peroxidase to pseudoazurin causes perturbation of a set of NMR resonances associated with residues on the His81 face, including a ring of lysine residues. These lysines are associated with acidic residues just back from the rim, the resonances of which are also affected by binding to the peroxidase. We propose that these acidic residues moderate the electrostatic influence of the lysines and so ensure that specific charge interactions do not form across the interface with the peroxidase.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 26 Pauleta, SR Guerlesquin, F Goodhew, CF Devreese, B Van Beeumen, J Pereira, AS Moura, I Pettigrew, GW&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Dias, JM</style></author><author><style face="normal" font="default" size="100%">Alves, T.</style></author><author><style face="normal" font="default" size="100%">Bonifacio, C.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Trincao, J</style></author><author><style face="normal" font="default" size="100%">Bourgeois, D.</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Romao, MJ</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Structural basis for the mechanism of Ca2+ activation of the di-heme cytochrome c peroxidase from Pseudomonas nautica 617</style></title><secondary-title><style face="normal" font="default" size="100%">Structure</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2004</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000222155100009</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">6</style></number><volume><style face="normal" font="default" size="100%">12</style></volume><pages><style face="normal" font="default" size="100%">961-973</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Cytochrome c peroxidase (CCP) catalyses the reduction of H2O2 to H2O, an important step in the cellular detoxification process. The crystal structure of the di-heme CCP from Pseudomonas nautica 617 was obtained in two different conformations in a redox state with the electron transfer heme reduced. Form IN, obtained at pH 4.0, does not contain Ca2+ and was refined at 2.2 Angstrom resolution. This inactive form presents a closed conformation where the peroxidatic heme adopts a six-ligand coordination, hindering the peroxidatic reaction from taking place. Form OUT is Ca2+ dependent and was crystallized at pH 5.3 and refined at 2.4 Angstrom resolution. This active form shows an open conformation, with release of the distal histidine (His71) ligand, providing peroxide access to the active site. This is the first time that the active and inactive states are reported for a di-heme peroxidase.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 35 Dias, JM Alves, T Bonifacio, C Pereira, AS Trincao, J Bourgeois, D Moura, I Romao, MJ&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Jameson, G. N. L.</style></author><author><style face="normal" font="default" size="100%">Jin, W</style></author><author><style face="normal" font="default" size="100%">Krebs, C</style></author><author><style face="normal" font="default" size="100%">Perreira, A. S.</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Liu, X. F.</style></author><author><style face="normal" font="default" size="100%">Theil, E. C.</style></author><author><style face="normal" font="default" size="100%">HUYNH, BH</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Stoichiometric production of hydrogen peroxide and parallel formation of ferric multimers through decay of the diferric-peroxo complex, the first detectable intermediate in ferritin mineralization</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2002</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000179137500013</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">45</style></number><volume><style face="normal" font="default" size="100%">41</style></volume><pages><style face="normal" font="default" size="100%">13435-13443</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The catalytic step that initiates formation of the ferric oxy-hydroxide mineral core in the central cavity of H-type ferritin involves rapid oxidation of ferrous ion by molecular oxygen (ferroxidase reaction) at a binuclear site (ferroxidase site) found in each of the 24 subunits. Previous investigators have shown that the first detectable reaction intermediate of the ferroxidase reaction is a diferric-peroxo intermediate, F-peroxo, formed within 25 ms, which then leads to the release of H2O2 and formation of ferric mineral precursors. The stoichiometric relationship between F-peroxo, H2O2, and ferric mineral precursors, crucial to defining the reaction pathway and mechanism, has now been determined. To this end, a horseradish peroxidase-catalyzed spectrophotometric method was used as an assay for H2O2. By rapidly mixing apo M ferritin from frog, Fe2+, and O-2 and allowing the reaction to proceed for 70 ms when F-peroxo has reached its maximum accumulation, followed by spraying the reaction mixture into the H2O2 assay solution, we were able to quantitatively determine the amount of H2O2 produced during the decay of F-peroxo. The correlation between the amount of H2O2 released with the amount of F-peroxo accumulated at 70 ms determined by Mossbauer spectroscopy showed that F-peroxo decays into H2O2 with a stoichiometry of 1 F-peroxo:H2O2. When the decay of F-peroxo was monitored by rapid freeze-quench Mossbauer spectroscopy, multiple diferric mu-oxo/mu-hydroxo complexes and small polynuclear ferric clusters were found to form at rate constants identical to the decay rate of F-peroxo. This observed parallel formation of multiple products (H2O2, diferric complexes, and small polynuclear clusters) from the decay of a single precursor (F-peroxo) provides useful mechanistic insights into ferritin mineralization and demonstrates a flexible ferroxidase site.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 44 Jameson, GNL Jin, W Krebs, C Perreira, AS Tavares, P Liu, XF Theil, EC Huynh, BH&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Di Rocco, G</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Bursakov, SA</style></author><author><style face="normal" font="default" size="100%">Gavel, OY</style></author><author><style face="normal" font="default" size="100%">Rusnak, F</style></author><author><style face="normal" font="default" size="100%">Lampreia, J</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Cloning of a novel Mo-Cu containing protein from Desulfovibrio.gigas</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Inorganic Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2001</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000170467300379</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">1</style></number><volume><style face="normal" font="default" size="100%">86</style></volume><pages><style face="normal" font="default" size="100%">202-202</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">n/a</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 0 Di Rocco, G Pereira, AS Bursakov, SA Gavel, OY Rusnak, F Lampreia, J Moura, JJG Moura, I&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">HUYNH, BH</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Mossbauer characterization of the iron-sulfur clusters in Desulfovibrio vulgaris hydrogenase</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of the American Chemical Society</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2001</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000167792400009</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">12</style></number><volume><style face="normal" font="default" size="100%">123</style></volume><pages><style face="normal" font="default" size="100%">2771-2782</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The periplasmic hydrogenase of Desulfovibrio vulgaris (Hildenbourough) is an all Fe-containing hydrogenase. It contains two ferredoxin type [4Fe-4S] clusters, termed the F clusters, and a catalytic H cluster. Recent X-ray crystallographic studies on two Fe hydrogenases revealed that the H cluster is composed of two sub-clusters, a [4Fe-4S] cluster ([4Fe-4S]H) and-a binuclear Fe cluster ([2Fe]H), bridged by a cysteine sulfur. The aerobically purified D. vulgaris hydrogenase is stable in air. It is inactive and requires reductive activation. Upon reduction, the enzyme becomes sensitive to O(2) indicating that the reductive activation process is irreversible. Previous EPR investigations showed that upon reoxidation (under argon) the H cluster exhibits a rhombic EPR signal that is not seen in the as-purified enzyme, suggesting a conformational change in association with the reductive activation. For the purpose of gaining more information on the electronic properties of this unique H cluster and to understand further the reductive activation process, variable-temperature and variable-field Mossbauer spectroscopy has been used to characterize the Fe-S clusters in D. vulgaris hydrogenase poised at different redox states generated during a reductive titration, and in the GO-reacted enzyme. The data were successfully decomposed into spectral components corresponding to the F and H clusters,and characteristic parameters describing the electronic and magnetic properties of the F and H clusters were obtained. Consistent with the X-ray crystallographic results, the spectra of the H cluster can be understood as originating from an exchange coupled [4Fe-4S] - [2Fe] system. In particular, detailed analysis of the data reveals that the reductive activation begins with reduction of the [4Fe-4S]H cluster from the 2+ to the If state, followed by transfer of the reducing equivalent from the [4Fe-4S]H subcluster to the binuclear [2Fe]H subcluster. The results also reveal that binding of exogenous CO to the H cluster affects significantly the exchange coupling between the [4Fe-4S]H and the [2Fe]H subclusters. Implication of such a CO binding effect is discussed.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 86 Pereira, AS Tavares, P Moura, I Moura, JJG Huynh, BH&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Cabrito, I</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Besson, S</style></author><author><style face="normal" font="default" size="100%">Brondino, C</style></author><author><style face="normal" font="default" size="100%">Hoffman, B</style></author><author><style face="normal" font="default" size="100%">Brown, K</style></author><author><style face="normal" font="default" size="100%">Tegoni, M</style></author><author><style face="normal" font="default" size="100%">Cambillau, C</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Nitrous oxide reductase (N2OR) from Pseudomonas nautica 617</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Inorganic Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2001</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000170467300305</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">1</style></number><volume><style face="normal" font="default" size="100%">86</style></volume><pages><style face="normal" font="default" size="100%">165-165</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">n/a</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 1 Cabrito, I Pereira, AS Tavares, P Besson, S Brondino, C Hoffman, B Brown, K Tegoni, M Cambillau, C Moura, JJG Moura, I&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Baldwin, J.</style></author><author><style face="normal" font="default" size="100%">Voegtli, W. C.</style></author><author><style face="normal" font="default" size="100%">Khidekel, N.</style></author><author><style face="normal" font="default" size="100%">Moenne-Loccoz, P.</style></author><author><style face="normal" font="default" size="100%">Krebs, C</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Ley, B. A.</style></author><author><style face="normal" font="default" size="100%">HUYNH, BH</style></author><author><style face="normal" font="default" size="100%">Loehr, T. M.</style></author><author><style face="normal" font="default" size="100%">Riggs-Gelasco, P. J.</style></author><author><style face="normal" font="default" size="100%">Rosenzweig, A. C.</style></author><author><style face="normal" font="default" size="100%">Bollinger, J. M.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Rational reprogramming of the R2 subunit of Escherichia coli ribonucleotide reductase into a self-hydroxylating monooxygenase</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of the American Chemical Society</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2001</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000169978900007</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">29</style></number><volume><style face="normal" font="default" size="100%">123</style></volume><pages><style face="normal" font="default" size="100%">7017-7030</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The outcome of O-2 activation at the diiron(II) cluster in the R2 subunit of Escherichia coli (class I) ribonucleotide reductase has been rationally altered from the normal tyrosyl radical (Y122)(1) production to self-hydroxylation of a phenylalanine side-chain by two amino acid substitutions that leave intact the (histidine)(2)-(carboxylate)(4) ligand set characteristic of the diiron-carboxylate family. Iron ligand Asp (D) 84 was replaced with Glu (E), the amino acid found in the cognate position of the structurally similar diiron-carboxylate protein, methane monooxygenase hydroxylase (MMOH). We previously showed that this substitution allows accumulation of a mu -1,2-peroxodiiron(III) intermediate,(2 3) which does not accumulate in the wild-type (wt) protein and is probably a structural homologue of intermediate P (H-peroxo) in O-2 activation by MMOH.(4) In addition, the near-surface residue Trp (W) 48 was replaced with Phe (F), blocking transfer of the &quot;extra&quot; electron that occurs in wt R2 during formation of the formally Fe(LII)Fe(IV) cluster X.(5-7) Decay of the mu1,2-peroxodiiron(III) complex in R2-W38F/D84E gives an initial brown product, which contains very little YI22(.) and which converts very slowly (t(1/2) similar to 7 h) upon incubation at 0 degreesC to an intensely purple final product. X-ray crystallographic analysis of the purple product indicates that F208 has undergone epsilon -hydroxylation and the resulting phenol has shifted significantly to become st ligand to Fe2 of the diiron cluster. Resonance Raman (RR) spectra of the purple product generated with O-16(2) or O-18(2) show appropriate isotopic sensitivity in bands assigned to O-phenyl and Fe-O-phenyl vibrational modes, confirming that the oxygen of the Fe(III)-phenolate species is derived from Or. Chemical analysis, experiments involving interception of the hydroxylating intermediate with exogenous reductant, and Mossbauer and EXAFS characterization of the brown and purple species establish that F208 hydroxylation occurs during decay of the peroxo complex and formation of the initial brown product. The slow transition to the purple Fe(LII)-phenolate species is ascribed to a ligand rearrangement in which mu -O2- is lost and the F208-derived phenolate coordinates. The reprogramming to F208 monooxygenase requires both amino acid substitutions, as very little epsilon -hydroxyphenylalanine is formed and pathways leading to Y122(.) formation predominate in both R2-D84E and R2-W48F(2-7).&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 61 Baldwin, J Voegtli, WC Khidekel, N Moenne-Loccoz, P Krebs, C Pereira, AS Ley, BA Huynh, BH Loehr, TM Riggs-Gelasco, PJ Rosenzweig, AC Bollinger, JM&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Alves, T.</style></author><author><style face="normal" font="default" size="100%">Besson, S</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Pettigrew, G. W.</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Structure-function studies of cytochrome c peroxidase from ps. nautica</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Inorganic Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2001</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000170467300219</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">1</style></number><volume><style face="normal" font="default" size="100%">86</style></volume><pages><style face="normal" font="default" size="100%">122-122</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">n/a</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 0 Alves, T Besson, S Pereira, AS Pettigrew, GW Moura, JJG Moura, I&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Franco, R</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Mangravita, A</style></author><author><style face="normal" font="default" size="100%">Barber, MJ</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Ferreira, GC</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Substitution of murine ferrochelatase glutamate-287 with glutamine or alanine leads to porphyrin substrate-bound variants</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemical Journal</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2001</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000169056200025</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">356</style></volume><pages><style face="normal" font="default" size="100%">217-222</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Ferrochelatase (EC 4.99.1.1) is the terminal enzyme of the haem biosynthetic pathway and catalyses iron chelation into the protoporphyrin IX ring. Glutamate-287 (E287) of murine mature ferrochelatase is a conserved residue in all known sequences of ferrochelatase, is present at the active site of the enzyme, as inferred from the Bacillus subtilis ferrochelatase three-dimensional structure, and is critical for enzyme activity. Substitution of E287 with either glutamine (Q) or alanine (A) yielded variants with lower enzymic activity than that of the wild-type ferrochelatase and with different absorption spectra from the wild-type enzyme. In contrast to the wild-type enzyme, the absorption spectra of the variants indicate that these enzymes, as purified, contain protoporphyrin IX. Identification and quantification of the porphyrin bound to the E287-directed variants indicate that approx. 80% of the total porphyrin corresponds to protoporphyrin IX. Significantly, rapid stopped-flow experiments of the E287A and E287Q Variants demonstrate that reaction with Zn2+ results in the formation of bound Zn-protoporphyrin IX, indicating that the endogenously bound protoporphyrin IX can be used as a substrate. Taken together, these findings suggest that the structural strain imposed by ferrochelatase on the porphyrin substrate as a critical step in the enzyme catalytic mechanism is also accomplished by the E287A and E287Q variants, but without the release of the product. Thus E287 in murine ferrochelatase appears to be critical For the catalytic process by controlling the release of the product.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 14 Franco, R Pereira, AS Tavares, P Mangravita, A Barber, MJ Moura, I Ferreira, GC Part 1&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Brown, K</style></author><author><style face="normal" font="default" size="100%">Tegoni, M</style></author><author><style face="normal" font="default" size="100%">Prudencio, M</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Besson, S</style></author><author><style face="normal" font="default" size="100%">Moura, J J</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Cambillau, C</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A novel type of catalytic copper cluster in nitrous oxide reductase</style></title><secondary-title><style face="normal" font="default" size="100%">Nature Structural Biology</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2000</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000085648900012</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">3</style></number><volume><style face="normal" font="default" size="100%">7</style></volume><pages><style face="normal" font="default" size="100%">191-195</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Nitrous oxide (N(2)O) is a greenhouse gas, the third most significant contributor to global warming. As a key process for N(2)O elimination from the biosphere, N(2)O reductases catalyze the two-electron reduction of N(2)O to N(2). These 2 x 65 kDa copper enzymes are thought to contain a CuA electron entry site, similar to that of cytochrome c oxidase, and a CuZ catalytic center. The copper anomalous signal was used to solve the crystal structure of N(2)O reductase from Pseudomonas nautica by multiwavelength anomalous dispersion, to a resolution of 2.4 Angstrom. The structure reveals that the CuZ center belongs to a new type of metal cluster, in which four copper ions are liganded by seven histidine residues. N(2)O binds to this center via a single copper ion. The remaining copper ions might act as an electron reservoir, assuring a fast electron transfer and avoiding the formation of dead-end products.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 166 Brown, K Tegoni, M Prudencio, M Pereira, AS Besson, S Moura, JJ Moura, I Cambillau, C&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Prudencio, M</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Besson, S</style></author><author><style face="normal" font="default" size="100%">Cabrito, I</style></author><author><style face="normal" font="default" size="100%">Brown, K</style></author><author><style face="normal" font="default" size="100%">Samyn, B</style></author><author><style face="normal" font="default" size="100%">Devreese, B</style></author><author><style face="normal" font="default" size="100%">VanBeeumen, J</style></author><author><style face="normal" font="default" size="100%">Rusnak, F</style></author><author><style face="normal" font="default" size="100%">Fauque, G</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Tegoni, M</style></author><author><style face="normal" font="default" size="100%">Cambillau, C</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Purification, characterization, and preliminary crystallographic study of copper-containing nitrous oxide reductase from Pseudomonas nautica 617</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2000</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000086478400005</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">14</style></number><volume><style face="normal" font="default" size="100%">39</style></volume><pages><style face="normal" font="default" size="100%">3899-3907</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The aerobic purification of Pseudomonas nautica 617 nitrous oxide reductase yielded two forms of the enzyme exhibiting different chromatographic behaviors. The protein contains six copper atoms per monomer, arranged in two centers named CUA and Cut. Cut could be neither oxidized nor further reduced under our experimental conditions, and exhibits a 4-line EPR spectrum (g(x)= 2.015, A(x) = 1.5 mT, g(y) = 2.071, A(y) = 2 mT, g(z) = 2.138, A(z) = 7 mT) and a strong absorption at similar to 640 nm. Cu-A can be stabilized in a reduced EPR-silent state and in an oxidized state with a typical 7-line EPR spectrum (g(x) g(y) = 2.021, A(x) = A(y) = 0 T, g(z) =0.178, A(z) = 4 mT) and absorption bands at 480, 540, and similar to 800 nm. The difference between the two purified forms of nitrous oxide reductase is interpreted as a difference in the oxidation state of the CuA center. In form A, CUA is predominantly oxidized (S = 1/2, Cu1.5+-Cu1.5+), while in form B it is mostly in the one-electron reduced state (S = 0, Cu1+-Cu1+). In both forms, Cu-Z remains reduced (S = 1/2). Complete crystallographic data at 2.4 Angstrom indicate that Cu-A is a binuclear site (similar to the site found in cytochrome c oxidase) and Cu-Z is a novel tetracopper cluster [Brown, K., et ai. (2000) Nat. Struct. Biol. (in press)]. The complete amino acid sequence of the enzyme was determined and comparisons made with sequences of other nitrous oxide reductases, emphasizing the coordination of the centers. A 10.3 kDa peptide copurified with both forms of nitrous oxide reductase shows strong homology with proteins of the heat-shock GroES chaperonin family.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 52 Prudencio, M Pereira, AS Tavares, P Besson, S Cabrito, I Brown, K Samyn, B Devreese, B Van Beeumen, J Rusnak, F Fauque, G Moura, JJG Tegoni, M Cambillau, C Moura, I&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Wengenack, NL</style></author><author><style face="normal" font="default" size="100%">Lopes, H</style></author><author><style face="normal" font="default" size="100%">Kennedy, MJ</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Rusnak, F</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Redox potential measurements of the Mycobacterium tuberculosis heme protein KatG and the isoniazid-resistant enzyme KatG(S315T): Insights into isoniazid activation</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2000</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000089436600036</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">37</style></number><volume><style face="normal" font="default" size="100%">39</style></volume><pages><style face="normal" font="default" size="100%">11508-11513</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Mycobacterium tuberculosis KatG is a multifunctional heme enzyme responsible for activation of the antibiotic isoniazid. A KatG(S315T) point mutation is found in &amp;gt;50% of isoniazid-resistant clinical isolates. Since isoniazid activation is thought to involve an oxidation reaction, the redox potential of KatG was determined using cyclic voltammetry, square wave voltammetry, and spectroelectrochemical titrations. Isoniazid activation may proceed via a cytochrome P450-like mechanism. Therefore, the possibility that substrate binding by KatG leads to an increase in the heme redox potential and the possibility that KatG(S315T) confers isoniazid resistance by altering the redox potential were examined. Effects of the heme spin state on the reduction potentials of KatG and KatG(S315T) were also determined. Assessment of the Fe3+/Fe2+ couple gave a midpoint potential of ca. -50 mV for both KatG and KatG(S315T). In contrast to cytochrome P450s, addition of substrate had no significant effect on either the KatG or KatG(S315T) redox potential. Conversion of the heme to a low-spin configuration resulted in a -150 to -200 mV shift of the KatG and KatG(S315T) redox potentials. These results suggest that isoniazid resistance conferred by KatG(S315T) is not mediated through changes in the heme redox potential. The redox potentials of isoniazid were also determined using cyclic and square wave voltammetry, and the results provide evidence that the ferric KatG and KatG(S315T) midpoint potentials are too low to promote isoniazid oxidation without formation of a high-valent enzyme intermediate such as compounds I and IT or oxyferrous KatG.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 28 Wengenack, NL Lopes, H Kennedy, MJ Tavares, P Pereira, AS Moura, I Moura, JJG Rusnak, F&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Krebs, C</style></author><author><style face="normal" font="default" size="100%">HUYNH, BH</style></author><author><style face="normal" font="default" size="100%">Rusnak, F</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Biochemical and spectroscopic characterization of overexpressed fuscoredoxin from Escherichia coli</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemical and Biophysical Research Communications</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1999</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000081138700035</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">1</style></number><volume><style face="normal" font="default" size="100%">260</style></volume><pages><style face="normal" font="default" size="100%">209-215</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Fuscoredoxin is a unique iron containing protein of yet unknown function originally discovered in the sulfate reducers of the genus Desulfovibrio. It contains two iron-sulfur clusters: a cubane [4Fe-4S] and a mixed oxo- and sulfide-bridged 4Fe cluster of unprecedented structure. The recent determination of the genomic sequence of Escherichia coli (E. coli) has revealed a homologue of fuscoredoxin in this facultative microbe. The presence of this gene in E. coli raises interesting questions regarding the function of fuscoredoxin and whether this gene represents a structural homologue of the better-characterized Desulfovibrio proteins. In order to explore the latter, an overexpression system for the E. coli fuscoredoxin gene was devised. The gene was cloned from genomic DNA by use of the polymerase chain reaction into the expression vector pT7-7 and overexpressed in E. coli BL21(DE3) cells. After two chromatographic steps a good yield of recombinant protein was obtained (approximately 4 mg of pure protein per liter of culture). The purified protein exhibits an optical spectrum characteristic of the homologue from D. desulfuricans, indicating that cofactor assembly was accomplished. Iron analysis indicated that the protein contains circa 8 iron atoms/molecule which were shown by EPR and Mossbauer spectroscopies to be present as two multinuclear clusters, albeit with slightly altered spectroscopic features. A comparison of the primary sequences of fuscoredoxins is presented and differences on cluster coordination modes are discussed on the light of the spectroscopic data. (C) 1999 Academic Press.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 8 Pereira, AS Tavares, P Krebs, C Huynh, BH Rusnak, F Moura, I Moura, JJG&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pamplona, A</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Rusnak, F</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Cloning and overexpression of E.Coli fuscoredoxin</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Inorganic Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1999</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000081157700485</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">1-4</style></number><volume><style face="normal" font="default" size="100%">74</style></volume><pages><style face="normal" font="default" size="100%">260-260</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">n/a</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 0 Pamplona, A Pereira, AS Tavares, P Moura, I Rusnak, F Moura, JJG&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Prudencio, M</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Besson, S</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Copper-containing nitrous oxide reductase from Pseudomonas nautica: spectroscopic and redox properties</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Inorganic Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1999</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000081157700500</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">1-4</style></number><volume><style face="normal" font="default" size="100%">74</style></volume><pages><style face="normal" font="default" size="100%">267-267</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">n/a</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 1 Prudencio, M Pereira, AS Tavares, P Besson, S Moura, I&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Almendra, MJ</style></author><author><style face="normal" font="default" size="100%">Brondino, CD</style></author><author><style face="normal" font="default" size="100%">Gavel, O</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Bursakov, S</style></author><author><style face="normal" font="default" size="100%">Duarte, R</style></author><author><style face="normal" font="default" size="100%">CALDEIRA, J</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Purification and characterization of a tungsten-containing formate dehydrogenase from Desulfovibrio gigas</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1999</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000084141200038</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">49</style></number><volume><style face="normal" font="default" size="100%">38</style></volume><pages><style face="normal" font="default" size="100%">16366-16372</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;An air-stable formate dehydrogenase (FDH), an enzyme that catalyzes the oxidation of formate to carbon dioxide, was purified from the sulfate reducing organism Desulfovibrio gigas (D. gigas) NCIB 9332. D. gigas FDH is a heterodimeric protein [alpha (92 kDa) and beta (29 kDa) subunits] and contains 7 +/- 1 Fe/protein and 0.9 +/- 0.1 W/protein, Selenium was not detected. The UV/visible absorption spectrum of D, gigas FDH is typical of an iron-sulfur protein. Analysis of pterin nucleotides yielded a content of 1.3 +/- 0.1 guanine monophosphate/mol of enzyme, which suggests a tungsten coordination with two molybdopterin guanine dinucleotide cofactors. Both Mossbauer spectroscopy performed on D. gigas FDH grown in a medium enriched with Fe-57 and EPR studies performed in the native and fully reduced state of the protein confirmed the presence of two [4Fe-4S] clusters. Variable-temperature EPR studies showed the presence of two signals compatible with an atom in a d(1) configuration albeit with an unusual relaxation behavior as compared to the one generally observed for W(V) ions.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 34 Almendra, MJ Brondino, CD Gavel, O Pereira, AS Tavares, P Bursakov, S Duarte, R Caldeira, J Moura, JJG Moura, I&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Coufal, DE</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Hyunh, BH</style></author><author><style face="normal" font="default" size="100%">Lippard, SJ</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Reactions of nitric oxide with the reduced non-heme diiron center of the soluble methane monooxygenase hydroxylase</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1999</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000079834100032</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">14</style></number><volume><style face="normal" font="default" size="100%">38</style></volume><pages><style face="normal" font="default" size="100%">4504-4513</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The soluble methane monooxygenase system from Methylococcus capsulatus (Bath) catalyzes the oxidation of methane to methanol and water utilizing dioxygen at a non-heme, carboxylate-bridged diiron center housed in the hydroxylase (H) component. To probe the nature of the reductive activation of dioxygen in this system, reactions of an analogous molecule, nitric oxide, with the diiron(II) form of the enzyme (H-red) Were investigated by both continuous and discontinuous kinetics methodologies using optical, EPR, and Mossbauer spectroscopy. Reaction of NO with H-red affords a dinitrosyl species, designated H-dinitrosyl, with optical spectra (lambda(max) = 450 and 620 nm) and Mossbauer parameters (delta = 0.72 mm/s, Delta E-Q = 1.55 mm/s) similar to those of synthetic dinitrosyl analogues and of the dinitrosyl adduct of the reduced ribonucleotide reductase R2 (RNR-R2) protein. The H-dinitrosyl species models features of the H-peroxo intermediate formed in the analogous dioxygen reaction. In the presence of protein B, H-dinitrosyl builds up with approximately the same rate constant as H-peroxo (similar to 26 s(-1)) at 4 degrees C. In the absence of protein B, the kinetics of H-dinitrosyl formation were best fit with a biphasic A –&amp;gt; B –&amp;gt; C model, indicating the presence of an intermediate species between H-red and H-dinitrosyl. This result contrasts with the reaction of H-red with dioxygen, in which the H-peroxo intermediate forms in measurable quantities only in the presence of protein B. These findings suggest that protein B may alter the positioning but not the availability of coordination sites on iron for exogenous ligand binding and reactivity.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 33 Coufal, DE Tavares, P Pereira, AS Hyunh, BH Lippard, SJ&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Wengenack, N</style></author><author><style face="normal" font="default" size="100%">Lopes, H</style></author><author><style face="normal" font="default" size="100%">Kennedy, M</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Rusnak, F</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Redox potential of the heme protein KatG from Mycobacterium tuberculosis</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Inorganic Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1999</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000081157700625</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">1-4</style></number><volume><style face="normal" font="default" size="100%">74</style></volume><pages><style face="normal" font="default" size="100%">336-336</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">n/a</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 0 Wengenack, N Lopes, H Kennedy, M Tavares, P Pereira, AS Moura, I Moura, JJG Rusnak, F&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Simple and complex iron-sulfur proteins in sulfate reducing bacteria</style></title><secondary-title><style face="normal" font="default" size="100%">Advances in Inorganic Chemistry, Vol 47</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1999</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000082271700008</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">47</style></volume><pages><style face="normal" font="default" size="100%">361-419</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">n/a</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 13 Moura, I Pereira, AS Tavares, P Moura, JJG&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Small, W</style></author><author><style face="normal" font="default" size="100%">Krebs, C</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Edmondson, DE</style></author><author><style face="normal" font="default" size="100%">Theil, E. C.</style></author><author><style face="normal" font="default" size="100%">HUYNH, BH</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Direct spectroscopic and kinetic evidence for the involvement of a peroxodiferric intermediate during the ferroxidase reaction in fast ferritin mineralization</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000074893800001</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">28</style></number><volume><style face="normal" font="default" size="100%">37</style></volume><pages><style face="normal" font="default" size="100%">9871-9876</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Rapid freeze-quench (RFQ) Mossbauer and stopped-flow absorption spectroscopy were used to monitor the ferritin ferroxidase reaction using recombinant (apo) frog M ferritin; the initial transient ferric species could be trapped by the RFQ method using low iron loading (36 Fe2+/ferritin molecule). Biphasic kinetics of ferroxidation were observed and measured directly by the Mossbauer method; a majority (85%) of the ferrous ions was oxidized at a fast rate of similar to 80 s(-1) and the remainder at a much slower rate of similar to 1.7 s(-1). In parallel with the fast phase oxidation of the Fe2+ ions, a single transient iron species is formed which exhibits magnetic properties (diamagnetic ground state) and Mossbauer parameters (Delta E-Q = 1.08 +/- 0.03 mm/s and delta = 0.62 +/- 0.02 mm/s) indicative of an antiferromagnetically coupled peroxodiferric complex. The formation and decay rates of this transient diiron species measured by the RFQ Mossbauer method match those of a transient blue species (lambda(max) = 650 nm) determined by the stopped-flow absorbance measurement. Thus, the transient colored species is assigned to the same peroxodiferric intermediate. Similar transient colored species have been detected by other investigators in several other fast ferritins (H and M subunit types), such as the human H ferritin and the Escherichia coli ferritin, suggesting a similar mechanism for the ferritin ferroxidase step in all fast ferritins. Peroxodiferric complexes are also formed as early intermediates in the reaction of O-2 With the catalytic diiron centers in the hydroxylase component of soluble methane monooxygenase (MMOH) and in the D84E mutant of the R2 subunit of E. coli ribonucleotide reductase. The proposal that a single protein site, with a structure homologous to the diiron centers in MMOH and R2, is involved in the ferritin ferroxidation step is confirmed by the observed kinetics, spectroscopic properties, and purity of the initial peroxodiferric species formed in the frog M ferritin.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 105 Pereira, AS Small, W Krebs, C Tavares, P Edmondson, DE Theil, EC Huynh, BH&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Valentine, AM</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Davydov, R</style></author><author><style face="normal" font="default" size="100%">Krebs, C</style></author><author><style face="normal" font="default" size="100%">Koffman, BM</style></author><author><style face="normal" font="default" size="100%">Edmondson, DE</style></author><author><style face="normal" font="default" size="100%">HUYNH, BH</style></author><author><style face="normal" font="default" size="100%">Lippard, SJ</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Generation of a mixed-valent Fe(III)Fe(IV) form of intermediate Q in the reaction cycle of soluble methane monooxygenase, an analog of intermediate X in ribonucleotide reductase R2 assembly</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of the American Chemical Society</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000072499100033</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">9</style></number><volume><style face="normal" font="default" size="100%">120</style></volume><pages><style face="normal" font="default" size="100%">2190-2191</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">n/a</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 45 Valentine, AM Tavares, P Pereira, AS Davydov, R Krebs, C Koffman, BM Edmondson, DE Huynh, BH Lippard, SJ&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Krebs, C</style></author><author><style face="normal" font="default" size="100%">Ravi, N</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">HUYNH, BH</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Spectroscopic characterization of a novel tetranuclear Fe cluster in an iron-sulfur protein isolated from Desulfovibrio desulfuricans</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000072523600014</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">9</style></number><volume><style face="normal" font="default" size="100%">37</style></volume><pages><style face="normal" font="default" size="100%">2830-2842</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Mossbauer and EPR spectroscopies were used to characterize the Fe clusters in an Fe-S protein isolated from Desulfovibrio desulfuricans (ATCC 27774). This protein was previously thought to contain hexanuclear Fe clusters, but a recent X-ray crystallographic measurement on a similar protein isolated from Desulfovibrio vulgaris showed that the protein contains two tetranuclear clusters, a cubane-type [4Fe-4S] cluster and a mixed-ligand cluster of novel structure [Lindley et al. (1997) Abstract, Chemistry of Metals in Biological Systems, European Research Conference, Tomar, Portugal]. Three protein samples poised at different redox potentials (as-purified, 40 and 320 mV) were investigated. In all three samples, the [4Fe-4S] cluster was found to be present in the diamagnetic 2+ oxidation state and exhibited typical Mossbauer spectra. The novel-structure cluster was found to be redox active. In the 320-mV and as-purified samples, the cluster is at a redox equilibrium between its fully oxidized and one-electron reduced states. In the 40-mV sample, the cluster is in a two-electron reduced state. Distinct spectral components associated with the four Fe sites of cluster 2 in the three oxidation states were identified. The spectroscopic parameters obtained for the Fe sites reflect different ligand environments, making it possible to assign the spectral components to individual Fe sites. In the fully oxidized state, all four iron ions are high-spin ferric and antiferromagnetically coupled to form a diamagnetic S = 0 state. In the one-electron and two-electron reduced states, the reducing electrons were found to localize, consecutively, onto two Fe sites that are rich in oxygen/nitrogen ligands. Based on the X-ray structure and the Mossbauer parameters, attempts could be made to identify the reduced Fe sites. For the two-electron reduced cluster, EPR and Mossbauer data indicate that the cluster is paramagnetic with a nonzero interger spin. For the one-electron reduced cluster, the data suggest a half-integer spin of 9/2 Characteristic fine and hyperfine parameters for all four Fe sites were obtained. Structural implications and the nature of the spin-coupling interactions are discussed.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 12 Tavares, P Pereira, AS Krebs, C Ravi, N Moura, JJG Moura, I Huynh, BH&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Lloyd, S. G.</style></author><author><style face="normal" font="default" size="100%">Danger, D</style></author><author><style face="normal" font="default" size="100%">Edmondson, DE</style></author><author><style face="normal" font="default" size="100%">Theil, E. C.</style></author><author><style face="normal" font="default" size="100%">HUYNH, BH</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Mossbauer spectroscopic and kinetic characterization of ferric clusters formed in h-chain ferritin mineralization</style></title><secondary-title><style face="normal" font="default" size="100%">Abstracts of Papers of the American Chemical Society</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1997</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:A1997WP18700666</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">213</style></volume><pages><style face="normal" font="default" size="100%">503-INOR</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">n/a</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 0 Tavares, P Pereira, AS Lloyd, SG Danger, D Edmondson, DE Theil, EC Huynh, BH Part 2&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Tavares, P.</style></author><author><style face="normal" font="default" size="100%">Lloyd, S. G.</style></author><author><style face="normal" font="default" size="100%">Danger, D</style></author><author><style face="normal" font="default" size="100%">Edmondson, DE</style></author><author><style face="normal" font="default" size="100%">Theil, E. C.</style></author><author><style face="normal" font="default" size="100%">HUYNH, BH</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Rapid and parallel formation of Fe3+ multimers, including a trimer, during H-type subunit ferritin mineralization</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1997</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:A1997XG90100035</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">25</style></number><volume><style face="normal" font="default" size="100%">36</style></volume><pages><style face="normal" font="default" size="100%">7917-7927</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Conversion of Fe ions in solution to the solid phase in ferritin concentrates iron required for cell function. The rate of the Fe phase transition in ferritin is tissue specific and reflects the differential expression of two classes of ferritin subunits (H and L). Early stages of mineralization were probed by rapid freeze-quench Mossbauer, at strong fields (up to 8 T), and EPR spectroscopy in an H-type subunit, recombinant frog ferritin; small numbers of Fe (36 moles/mol of protein) were used to increase Fe3+ in mineral precursor forms, At 25 ms, four Fe3+-oxy species (three Fe dimers and one Fe trimer) were identified, These Fe3+-oxy species were found to form at similar rates and decay subsequently to a distinctive superparamagentic species designated the ''young core.'' The rate of oxidation of Fe2+ (1026 s(-1)) corresponded well to the formation constant for the Fe3+- tyrosinate complex (920 s(-1)) observed previously [Waldo, G. S., &amp;amp; Theil, E. C. (1993) Biochemistry 32, 13261] and, coupled with EPR data, indicates that several or possibly all of the Fe3+-oxy species involve tyrosine. The results, combined with previous Mossbauer studies of Y30F human H-type ferritin which showed decreases in several Fe3+ intermediates and stabilization of Fe2+ [Bauminger, E. R., et al. (1993) Biochem, J. 296, 709], emphasize the involvement of tyrosyl residues in the mineralization of H-type ferritins. The subsequent decay of these multiple Fe3+-oxy species to the superparamagnetic mineral suggests that Fe3+ species in different environments may be translocated as intact units from the protein shell into the ferritin cavity where the conversion to a solid mineral occurs.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 31 Pereira, AS Tavares, P Lloyd, SG Danger, D Edmondson, DE Theil, EC Huynh, BH&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Franco, R</style></author><author><style face="normal" font="default" size="100%">Feio, MJ</style></author><author><style face="normal" font="default" size="100%">Pinto, C</style></author><author><style face="normal" font="default" size="100%">Lampreia, J</style></author><author><style face="normal" font="default" size="100%">Reis, MA</style></author><author><style face="normal" font="default" size="100%">Calvete, J</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Beech, I</style></author><author><style face="normal" font="default" size="100%">Lino, AR</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Characterization of representative enzymes from a sulfate reducing bacterium implicated in the corrosion of steel</style></title><secondary-title><style face="normal" font="default" size="100%">Biochemical and Biophysical Research Communications</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1996</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:A1996UF91100036</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">2</style></number><volume><style face="normal" font="default" size="100%">221</style></volume><pages><style face="normal" font="default" size="100%">414-421</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;This communication reports the isolation, purification and characterization of key enzymes involved in dissimilatory sulfate reduction of a sulfate reducing bacterium classified as Desulfovibrio desulfuricans subspecies desulfuricans New Jersey (NCIMB 8313) (Ddd NJ). The chosen strain, originally recovered from a corroding cast iron heat exchanger, was grown in large scale batch cultures. Physico-chemical and spectroscopic studies of the purified enzymes were carried out. These analyses revealed a high degree of similarity between proteins isolated from the DddNJ strain and the homologous proteins obtained from Desulfomicrobium baculatus Norway 4. In view of the results obtained, taxonomic reclassification of Desulfovibrio desulfuricans subspecies desulfuricans New Jersey (NCIMB 8313) into Desulfomicrobium baculatus (New Jersey) is proposed. (C) 1996 Academic Press, Inc.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 12 Pereira, AS Franco, R Feio, MJ Pinto, C Lampreia, J Reis, MA Calvete, J Moura, I Beech, I Lino, AR Moura, JJG&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Lampreia, J</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">ADENYLYLSULFATE REDUCTASES FROM SULFATE-REDUCING BACTERIA</style></title><secondary-title><style face="normal" font="default" size="100%">Inorganic Microbial Sulfur Metabolism</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1994</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:A1994BB62R00016</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">243</style></volume><pages><style face="normal" font="default" size="100%">241-260</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">n/a</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 29 LAMPREIA, J PEREIRA, AS MOURA, JJG&lt;/p&gt;
</style></notes></record><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Ferreira, GC</style></author><author><style face="normal" font="default" size="100%">Franco, R</style></author><author><style face="normal" font="default" size="100%">Lloyd, S. G.</style></author><author><style face="normal" font="default" size="100%">Pereira, AS</style></author><author><style face="normal" font="default" size="100%">Moura, I</style></author><author><style face="normal" font="default" size="100%">Moura, JJG</style></author><author><style face="normal" font="default" size="100%">HUYNH, BH</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">MAMMALIAN FERROCHELATASE, A NEW ADDITION TO THE METALLOENZYME FAMILY</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Biological Chemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1994</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:A1994NA03200005</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">10</style></number><volume><style face="normal" font="default" size="100%">269</style></volume><pages><style face="normal" font="default" size="100%">7062-7065</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;A [2Fe-2S] cluster has been detected in mammalian ferrochelatase, the terminal enzyme of the heme biosynthetic pathway. Natural ferrochelatase, purified from mouse livers, and recombinant ferrochelatase, purified from an overproducing strain of Escherichia coli, were investigated by electron paramagnetic resonance (EPR) and Mossbauer spectroscopy. In their reduced forms, both the natural and recombinant ferrochelatases exhibited an identical EPR signal with g values (g = 2.00, 1.93, and 1.90) and relaxation properties typical of [2Fe-2S](+) cluster. Mossbauer spectra of the recombinant ferrochelatase, purified from a strain of E. coli cells transformed with a plasmid encoding murine liver ferrochelatase and grown in Fe-57-enriched medium, demonstrated unambiguously that the cluster is a [2Fe-2S] cluster. No change in the cluster oxidation state was observed during catalysis, The putative protein binding site for the Fe-S cluster in mammalian ferrochelatases is absent from the sequences of the bacterial and yeast enzymes, suggesting a possible role of the [2Fe-2S] center in regulation of mammalian ferrochelatases.&lt;/p&gt;
</style></abstract><work-type><style face="normal" font="default" size="100%">Journal Article</style></work-type><notes><style face="normal" font="default" size="100%">&lt;p&gt;Times Cited: 61 FERREIRA, GC FRANCO, R LLOYD, SG PEREIRA, AS MOURA, I MOURA, JJG HUYNH, BH&lt;/p&gt;
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