Orientation-Controllable Enzyme Cascade on Electrode for Bioelectrocatalytic Chain Reaction

Abstract

The accomplishment of concurrent interenzyme chain reactionanddirect electric communication in a multienzyme-electrode is challengingsince the required condition of multienzymatic binding conformationis quite complex. In this study, an enzyme cascade-induced bioelectrocatalyticsystem has been constructed using solid binding peptide (SBP) as amolecular binder that coimmobilizes the invertase (INV) and flavinadenine dinucleotide (FAD)-dependent glucose dehydrogenase gamma-alphacomplex (GDH & gamma;& alpha;) cascade system on a single electrode surface.The SBP-fused enzyme cascade was strategically designed to inducediverse relative orientations of coupling enzymes while enabling efficientdirect electron transfer (DET) at the FAD cofactor of GDH & gamma;& alpha;and the electrode interface. The interenzyme relative orientationwas found to determine the intermediate delivery route and affectoverall chain reaction efficiency. Moreover, interfacial DET betweenthe fusion GDH & gamma;& alpha; and the electrode was altered by thebinding conformation of the coimmobilized enzyme and fusion INVs.Collectively, this work emphasizes the importance of interenzyme orientationwhen incorporating enzymatic cascade in an electrocatalytic systemand demonstrates the efficacy of SBP fusion technology as a generictool for developing cascade-induced direct bioelectrocatalytic systems.The proposed approach is applicable to enzyme cascade-based bioelectronicssuch as biofuel cells, biosensors, and bioeletrosynthetic systemsutilizing or producing complex biomolecules.