OXIDATION OF 1,2,4,5-TETRAMETHOXYBENZENE BY LIGNIN PEROXIDASE OF PHANEROCHAETE-CHRYSOSPORIUM

We have reinvestigated the lignin peroxidase-catalyzed oxidation of 1, 2,4,5-tetramethoxybenzene (TMB) by using presteady-state and steady-st ate kinetic methods, Our presteady-state kinetic results show that the reaction of compound I with TMB obeyed second order kinetics with a r ate constant of 1.1 X 10(7) M(-1) s(-1) The reaction of compound II wi th TMB exhibits a hyperbolic concentration dependence with a K-d of 16 mu M and k = 24 s(-1). The stoichiometry of TMB oxidation during stea dy state is two TMB cation radicals formed per H2O2 consumed, These re sults clearly show that TMB is a good substrate for both compounds I a nd II of lignin peroxidase. (C) 1996 Academic Press, Inc.