Incorporation of molybdenum in rubredoxin: models for mononuclear molybdenum enzymes

Citation:
Maiti, B. K., L. B. Maia, C. M. Silveira, S. Todorovic, C. Carreira, M. S. Carepo, R. Grazina, I. Moura, S. R. Pauleta, and J. J. Moura. "Incorporation of molybdenum in rubredoxin: models for mononuclear molybdenum enzymes." J Biol Inorg Chem. 20 (2015): 821-9.

Abstract:

Molybdenum is found in the active site of enzymes usually coordinated by one or two pyranopterin molecules. Here, we mimic an enzyme with a mononuclear molybdenum-bis pyranopterin center by incorporating molybdenum in rubredoxin. In the molybdenum-substituted rubredoxin, the metal ion is coordinated by four sulfurs from conserved cysteine residues of the apo-rubredoxin and two other exogenous ligands, oxygen and thiol, forming a Mo((VI))-(S-Cys)4(O)(X) complex, where X represents -OH or -SR. The rubredoxin molybdenum center is stabilized in a Mo(VI) oxidation state, but can be reduced to Mo(IV) via Mo(V) by dithionite, being a suitable model for the spectroscopic properties of resting and reduced forms of molybdenum-bis pyranopterin-containing enzymes. Preliminary experiments indicate that the molybdenum site built in rubredoxin can promote oxo transfer reactions, as exemplified with the oxidation of arsenite to arsenate.

Notes:

Maiti, Biplab KMaia, Luisa BSilveira, Celia MTodorovic, SmiljaCarreira, CintiaCarepo, Marta S PGrazina, RaquelMoura, IsabelPauleta, Sofia RMoura, Jose J GResearch Support, Non-U.S. Gov'tGermanyJournal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic ChemistryJ Biol Inorg Chem. 2015 Jul;20(5):821-9. doi: 10.1007/s00775-015-1268-0. Epub 2015 May 7.

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