Monoamine oxidase catalysis on electrodes modified with artificial acceptors of electrons

Catalytic properties of monoamine oxidase B-type (MAO-B) were studied on el ectrodes modified with artificial accepters of electrons (AAE). It has been shown that AAE can substitute of oxygen in enzymatic reaction of amines ox idation. Some organic compounds were examined, namely 7,7',8,8'-tetracyanoq uinodimethane (TCNQ), methyl-1,4-benzoquinone (MBQ), 1,4-naphthoquinone (NQ ) and phenazine methosulfate (PMS). At anaerobic conditions in the system c ontaining MAO-B and its specific substrate benzylamine (BA) an abrupt incre ase of the anodic current was observed for TCNQ, MBQ and NQ adsorbed on the electrode. The current did not increase when MAO was replaced with bovine serum albumine or enzyme was inactivated by MAO-B specific inhibitor depren yl. The dependence of the anodic current on concentrations of AAE (TCNQ, MB Q and NQ) and benzylamine was detected. It was demonstrated that TCNQ as we ll as MBQ and NQ act as MAO substrates which are capable to substitute an o xygen in the catalytic reaction at anaerobic conditions. It was found that PMS hardly interacts with reduced form of MAO though this compound posses g ood electromediator properties. (C) 1998 Elsevier Science S.A. All rights r eserved.