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-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 10(7) M-1s-1. The reaction of compound II with TMB exhibits a hyperbolic concentration dependence with a Kd of 16 microM 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.
Koduri
R S
RS
Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802, USA.
Whitwam
R E
RE
Barr
D
D
Aust
S D
SD
Tien
M
M
D000840:Anisoles / Q000737:chemistry / Q000378:metabolism*; D001487:Basidiomycota / Q000201:enzymology*; D002412:Cations; D005609:Free Radicals; D007700:Kinetics; D010084:Oxidation-Reduction; D010544:Peroxidases / Q000378:metabolism*; D013379:Substrate Specificity
D000840:Anisoles; D002412:Cations; D005609:Free Radicals; C088469:1,2,4,5-tetramethoxybenzene; D010544:Peroxidases; C042858:lignin peroxidase