Open AccessDirect electrochemistry of the Desulfovibrio gigas aldehyde oxidoreductase
Author(s) -
Correia dos Santos Margarida M.,
Sousa Patrícia M. P.,
Gonçalves M. Lurdes S.,
Romão M. João,
Moura Isabel,
Moura José J. G.
Publication year - 2004
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.2004.04041.x
Subject(s) - chemistry , redox , desulfovibrio , cofactor , electrochemistry , oxidoreductase , electron transfer , glassy carbon , inorganic chemistry , voltammetry , cyclic voltammetry , electrode , photochemistry , enzyme , organic chemistry , sulfate
This work reports on the direct electrochemistry of the Desulfovibrio gigas aldehyde oxidoreductase ( Dg AOR), a molybdenum enzyme of the xanthine oxidase family that contains three redox‐active cofactors: two [2Fe‐2S] centers and a molybdopterin cytosine dinucleotide cofactor. The voltammetric behavior of the enzyme was analyzed at gold and carbon (pyrolytic graphite and glassy carbon) electrodes. Two different strategies were used: one with the molecules confined to the electrode surface and a second with Dg AOR in solution. In all of the cases studied, electron transfer took place, although different redox reactions were responsible for the voltammetric signal. From a thorough analysis of the voltammetric responses and the structural properties of the molecular surface of Dg AOR, the redox reaction at the carbon electrodes could be assigned to the reduction of the more exposed iron cluster, [2Fe‐2S] II, whereas reduction of the molybdopterin cofactor occurs at the gold electrode. Voltammetric results in the presence of aldehydes are also reported and discussed.