Медиаторное окисление 4-гидроксибифенила, катализируемое лакказой

Abstract

The kinetics of Poдyporus pinsitus laccase-catalyzed 4-hydroxybiphenyl oxidation was investigated in the presence of methyl syringate (MS) acting as electron-transfer mediator. Measurements were performed in 0.05 M acetate buffer solution, pH 5.5, in the presence of 4-HBP, methyl syringate, and laccase. Results of the measurements show that the rate of the oxidation of lowly reactive substrate (4-HBP) considerably increases during synergistic action of the highly reactive substrate (methyl syringate). Kinetic constants of the processes of interaction of the oxidized form of laccase with MS, of the oxidized form of laccase with 4-HBP, and of the oxidized form of mediator with 4-HBP have been calculated. A kinetic scheme of synergistic substrates action is suggested, and the dependence of the initial rate on the concentration of components of the reaction is derived. The kinetic constants calculated from experimental data and acquired during mathematical modeling are similar.