Structural bioelectrochemistry of direct electron transfer-type multimeric dehydrogenases: Basic principle and rational strategies

Abstract

Direct electron transfer (DET)-type bioelectrocatalysis, a coupled enzymatic and electrode reaction without redox mediators, provides insights into enzyme properties that facilitate the construction of efficient biomimetic devices. Because many DET-type multimeric dehydrogenases are membrane-bound proteins, obtaining the overall steric structures of these enzymes using conventional X-ray crystallography has proved difficult for many decades. Novel cryo-electron microscopy (cryo-EM) and single-particle image analysis have recently been developed that enable elucidation of the overall structure of membrane-bound DET-type multimeric dehydrogenases. In particular, “structural bioelectrochemistry,” a fusion of structural biology and bioelectrochemistry, has enabled rapid hypothesis testing via the analysis of three-dimensional (3D) structures using enzyme engineering and electrochemistry. This review outlines critical related studies in the last decade and the epoch-making breakthroughs leading to next-generation applications.