Direct Electron Transfer Process Of Pyrroloquinoline Quinone-Dependent And Flavin Adenine Dinucleotide-Dependent Dehydrogenases: Fundamentals And Applications

Pyrroloquinoline quinone-dependent and flavin adenine dinucleotide-dependent enzymes catalyze the oxidation of various compounds. These enzymes are large molecules, and the embedding of active sites in the insulating portion of the molecule generally make direct bioelectrocatalysis difficult. Dehydrogenases with a built-in electron transfer domain are capable of direct electron transfer (DET) to an electrode. Attempts have also been made to realize DET by artificially producing fusion proteins in which protein engineering is fully exploited to connect electron transfer domains. Furthermore, the reports of the DET of enzymes without an electron transfer domain to an electrode have started to appear. This review summarizes recent reports on fundamental findings on DET and applications using DET-enzyme electrodes.