Publications

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2020
Teixeira, L. R., C. M. Cordas, M. P. Fonseca, N. E. C. Duke, P. R. Pokkuluri, and C. A. Salgueiro. "Modulation of the Redox Potential and Electron/Proton Transfer Mechanisms in the Outer Membrane Cytochrome OmcF From Geobacter sulfurreducens." Frontiers in Microbiology. 10 (2020). AbstractWebsite
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2018
Rosa, V., A. P. S. Gaspari, F. Folgosa, C. M. Cordas, P. Tavares, T. Santos-Silva, S. Barroso, and T. Avilés. "Imine ligands based on ferrocene: Synthesis, structural and Mössbauer characterization and evaluation as chromogenic and electrochemical sensors for Hg2+." New Journal of Chemistry. 42.5 (2018): 3334-3343. AbstractWebsite
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Teixeira, L. R., J. M. Dantas, C. A. Salgueiro, and C. M. Cordas. "Thermodynamic and kinetic properties of the outer membrane cytochrome OmcF, a key protein for extracellular electron transfer in Geobacter sulfurreducens." Biochimica et Biophysica Acta - Bioenergetics. 1859.10 (2018): 1132-1137. AbstractWebsite
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2011
Folgosa, F., C. M. Cordas, J. A. Santos, AS Pereira, JJG Moura, P. Tavares, and I. Moura. "New spectroscopic and electrochemical insights on a class I superoxide reductase: evidence for an intramolecular electron-transfer pathway." Biochemical Journal. 438 (2011): 485-494. AbstractWebsite

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.

Cordas, C. M., J. Wilton, T. Cardoso, F. Folgosa, AS Pereira, and P. Tavares. "Electrochemical behaviour of Dps-a mini-ferritin." European Biophysics Journal with Biophysics Letters. 40 (2011): 181. AbstractWebsite
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2006
Cordas, C. M., AS Pereira, C. E. Martins, C. G. Timoteo, I. Moura, JJG Moura, and P. Tavares. "Nitric oxide reductase: Direct electrochemistry and electrocatalytic activity." Chembiochem. 7.12 (2006): 1878-1881. AbstractWebsite
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2004
Auchere, F., R. Sikkink, C. Cordas, P. Raleiras, P. Tavares, I. Moura, and JJG Moura. "Overexpression and purification of Treponema pallidum rubredoxin; kinetic evidence for a superoxide-mediated electron transfer with the superoxide reductase neelaredoxin." Journal of Biological Inorganic Chemistry. 9.7 (2004): 839-849. Abstract
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2003
Cordas, C. M., A. Tenreiro, and L. M. Abrantes EQCM study on the polytyramine modified electrodes for the preparation of biosensors. Eds. Y. G. Gogotsi, and I. V. Uvarova. Vol. 102. Nanostructured Materials and Coatings for Biomedical and Sensor Applications, 102., 2003. AbstractWebsite
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