Cytochrome electroreduction

Several heterodinuclear Fe-Cu or Co-Cu complexes that closely resemble the native enzyme active sites have recently been prepared to elucidate the catalytic mechanism of cytochrome c oxidases [231-245], The use of a covalently attached axial ligand seems essential to achieve efficient electroreduction of O2 to H2O [235, 238, 241-243], The closest structural analogs of the heme as/Cus active site of cytochrome c oxidases reported so far are Fe-Cu complexes (1 and 2) in which the Cu coordination site is provided by three imidazole ligands [242], These biomimetic model complexes afford clean electroreduction of O2 to H2O over a wide range of pH with no leakage of H2O2 [243],... 

The results on the activation of electroreduction of oxygen by cytochrome c, as well as data on the investigation of the electrochemical properties of cytochrome, permit us to conclude that in this case there is a direct electron exchange between the active center and the electrode. 

The results obtained on the activation of electroreduction of oxygen by adsorbed laccase, of hydrogen peroxide by adsorbed peroxidase, and of lactate by adsorbed cytochrome confirm the possibility of producing heterogeneous bioelectrocatalysts with activities significantly superior to those of known electrocatalysts. 

Ricard, D., A. Didier, M. L Her, and B. Boitrel (2001). Application of 3-quinolinoyl picket porphyrins to the electroreduction of dioxygen to water Mimicking the active site of cytochrome c oxidase. Chembiochem 2, 144-148. 

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