Biomaterial Database

Inactivation of lignin peroxidase by hydrogen peroxide during the oxidation of phenols. 1995

N Chung, and S D Aust

Biotechnology Center, Utah State University, Logan 84322-4705.

The oxidation of phenols by lignin peroxidase (LiP) was characterized by a rapid decrease in enzyme activity. The initial oxidation rate of phenol decreased at moderately high (i.e., 400 microM) concentrations of H2O2. Similar results were obtained with several phenols. However, LiP was not inactivated during the oxidation of veratryl alcohol (VA). The apparent second-order rate constants for the reaction of compound II with phenol and VA at pH 3.5 were very similar, about 2.1 x 10(4) and 4.7 x 10(4) M-1 s-1, respectively. However, unlike VA, phenols could not convert compound III back to ferric enzyme. The visible absorption spectra of compound II and III were observed during oxidation of VA and phenols, respectively. These results suggest that the inactivation of LiP during the oxidation of phenols was mainly due to the accumulation of compound III, which was attributed to the inability of phenols or phenoxyl radicals to revert compound III to ferric enzyme. All of these results also suggested that the inactivation mechanism of LiP during oxidation of phenols was different from that during oxidation of anisyl alcohol, since anisyl alcohol was neither a substrate of compound II nor could it revert compound III [K. Valli et al. (1990) Biochemistry 29, 8535-8539 and R.S. Koduri and M. Tien (1994) Biochemistry 33, 4225-4230].

UI	MeSH Term	Description	Entries
D008667	Metalloproteins	Proteins that have one or more tightly bound metal ions forming part of their structure. (Dorland, 28th ed)	Metalloprotein
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
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
D010636	Phenols	Benzene derivatives that include one or more hydroxyl groups attached to the ring structure.
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D005658	Fungi	A kingdom of eukaryotic, heterotrophic organisms that live parasitically as saprobes, including MUSHROOMS; YEASTS; smuts, molds, etc. They reproduce either sexually or asexually, and have life cycles that range from simple to complex. Filamentous fungi, commonly known as molds, refer to those that grow as multicellular colonies.	Fungi, Filamentous,Molds,Filamentous Fungi,Filamentous Fungus,Fungus,Fungus, Filamentous,Mold
D006861	Hydrogen Peroxide	A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.	Hydrogen Peroxide (H2O2),Hydroperoxide,Oxydol,Perhydrol,Superoxol,Peroxide, Hydrogen
D001592	Benzyl Alcohols	Alcohols derived from the aryl radical (C6H5CH2-) and defined by C6H5CHOH. The concept includes derivatives with any substituents on the benzene ring.	Phenylcarbinols,Phenylmethanols,Alcohols, Benzyl
D013053	Spectrophotometry	The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.