Direct electrochemistry of the enzyme, methylamine dehydrogenase, from bacterium W3A1

Abstract

The electrochemical response of methylamine dehydrogenase from bacterium W3A1 at edge‐plane‐oriented pyrolytic graphite (epg) and modified gold electrodes has been investigated. Quasi‐reversible electron transfer has been observed. Variations in concentration of different cations and anions gave rise to both promotion and inhibition of the direct response. A catalytic response of the enzyme in the presence of methylamine has been observed at both an epg electrode and a 2,2′‐dithiodiglycolic‐acid‐modified gold electrode surface, and the effects of various cations and anions on the catalytic peak current have been investigated. The spectroelectrochemical results obtained at an optically transparent thin‐layer electrode, modified with 2,2′‐dithiodiglycolic acid, are also reported. In the presence of 1,1′‐dimethylferrocene‐3‐(1‐ethanol‐2‐amine) (14.8 μM), the results reveal a midpoint potential of –148 mV for methylamine dehydrogenase from bacterium W3A1. This is in very close agreement to the value obtained in the cyclic voltammetric investigations of –140 mV. Copyright © 1991, Wiley Blackwell. All rights reserved