Electron Flow - Routing the flow of electrons from oxidoreductases to electrodes

Duration:   2018-2021

Abstract:

The project investigates the function of the cytochrome domain (CYT) of cellobiose dehydrogenase (CDH) as an electron transferring domain for oxidoreductases. The combination of CYT and glucose-methanol-choline (GMC) oxidoreductases into chimeric flavocytochromes will reroute the flow of electrons from the catalytic centre to an electrode. The enzymes dependence on cosubstrates like oxygen, quinones or redox mediators shall be replaced by direct electron transfer to an electrode – a cheap and truly atom efficient source of reduction equivalents. CYT-modified GMC oxidoreductases with efficient DET are highly interesting for biosensors and bioelectrocatalytic processes. The electron transfer efficiency in the existing flavocytochrome CDH, but also in the generated CYT-GMC chimeric enzymes, is governed by the CYT domain mobility – modulated by the interdomain protein linker length and the geometric and electrostatic complementarity of the domain interface. The mechanism and kinetics of CYT interaction with three GMC oxidoreductases (aryl alcohol oxidase, alcohol oxidase and glucose dehydrogenase) will be studied in comparison with CDH. In a second line of the project, the interaction of electrode-immobilized CYT to the unwired GMC oxidoreductases and to lytic polysaccharide monooxygenase will be investigated as a platform to electrically contact oxidoreductases. The project aims to elucidate the domain interaction mechanism, CYT orientation and mobility by fast kinetic and electrochemical methods and to investigate the potential of CYT-GMC chimeric enzymes and CYT-modified electrodes for biosensing and bioelectrocatalytic applications.