Biomaterial Database

Oxidation of 1,2,4,5-tetramethoxybenzene by lignin peroxidase of Phanerochaete chrysosporium. 1996

R S Koduri, and R E Whitwam, and D Barr, and S D Aust, and M Tien

Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802, USA.

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.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D010544	Peroxidases		Ovoperoxidase
D002412	Cations	Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.	Cation
D005609	Free Radicals	Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. Free radicals include reactive oxygen and nitrogen species (RONS). They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.	Free Radical
D000840	Anisoles	A group of compounds that are derivatives of methoxybenzene and contain the general formula R-C7H7O.	Methylphenyl Ethers,Ethers, Methylphenyl
D001487	Basidiomycota	A phylum of fungi that produce their sexual spores (basidiospores) on the outside of the basidium. It includes forms commonly known as mushrooms, boletes, puffballs, earthstars, stinkhorns, bird's-nest fungi, jelly fungi, bracket or shelf fungi, and rust and smut fungi.	Basidiomycetes,Basidiomycete,Basidiomycotas
D013379	Substrate Specificity	A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.	Specificities, Substrate,Specificity, Substrate,Substrate Specificities