We have reinvestigated the lignin peroxidase-catalyzed oxidation of 1,2,4,5-tetramethoxybenzene (TMB) by using presteady-state and steady-state kinetic methods. Our presteady-state kinetic results show that the reaction of compound I with TMB obeyed second order kinetics with a rate constant of 1.1 x 107 M-1 s-1. The reaction of compound II with TMB exhibits a hyperbolic concentration dependence with a K(d) of 16 μM and k = 24 s-1. The stoichiometry of TMB oxidation during steady state is two TMB cation radicals formed per H2O2 consumed. These results clearly show that TMB is a good substrate for both compounds I and II of lignin peroxidase.
All Science Journal Classification (ASJC) codes
- Molecular Biology