US EPA

2854582 

Journal Article 

Incorporation of molybdenum in rubredoxin: models for mononuclear molybdenum enzymes 

Maiti, BK; Maia, LB; Silveira, CM; Todorovic, S; Carreira, C; Carepo, MS; Grazina, R; Moura, I; Pauleta, SR; Moura, JJ 

2015 

Yes 

Journal of Biological Inorganic Chemistry
ISSN: 0949-8257
EISSN: 1432-1327 

20 

5 

821-829 

English 

25948393 

10.1007/s00775-015-1268-0 

WOS:000356882300006 

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.