Electroenzymatic reduction enzymes

Simon and collaborators have described a novel stereoselective electroenzymatic reduction of alkenes of type 23 (equation 12)28. The enzyme enoate reductase is the reductant... 

Figure 8. Methyl viologen-mediated electroenzymatic reduction of pyruvate to o-lactate using lipoamide dehydrogenase (LiDH) and cross-linked enzyme crystals of o-lactate dehydrogenase [49],...

Coupling of the electroenzymatic reduction of NAD with a synthesis reaction. Enzyme Microb. Technol., 18, 72-79. 

Electroenzymatic reactions are not only important in the development of ampero-metric biosensors. They can also be very valuable for organic synthesis. The enantio- and diasteroselectivity of the redox enzymes can be used effectively for the synthesis of enantiomerically pure compounds, as, for example, in the enantioselective reduction of prochiral carbonyl compounds, or in the enantio-selective, distereoselective, or enantiomer differentiating oxidation of chiral, achiral, or mes< -polyols. The introduction of hydroxy groups into aliphatic and aromatic compounds can be just as interesting. In addition, the regioselectivity of the oxidation of a certain hydroxy function in a polyol by an enzymatic oxidation can be extremely valuable, thus avoiding a sometimes complicated protection-deprotection strategy. 

The vast majority of enzyme biofuel cells is based on the electroenzymatic oxidation of glucose by glucose oxidase (GOX) and oxygen reduction by laccase, rarely, bilirubin oxidase, or even ascorbate oxidase. Usually two couples of redox mediators are involved in the functioning of the enzymatic biofuel cell. One is required to establish an electrical connection between the electrode surface and the reduced form of flavin adenine dinucleotide, the prosthetic center of GOX. The second couple, located at the cathode, allows the electron transfer from the electrode siuface to the copper center of laccase where the oxygen reduction takes place (Fig. 3.2). 

The power of biofuel cells is directly related to the difference between the respective redox potentials of the electroenzymatic reactions occurring at each of the two electrodes the bioanode for glucose oxidation and the biocathode for the reduction of oxygen. The cell voltage and hence the power thus depends on the mode of enzyme wiring and therefore, the direct electron transfer is the most... 

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