Biomaterial Database

Stoichiometry of the topa quinone biogenesis reaction in copper amine oxidases. 1999

C E Ruggiero, and D M Dooley

Department of Chemistry and Biochemistry, Montana State University, Bozeman 59717, USA.

The stoichiometry of the topa quinone biogenesis reaction in phenylethylamine oxidase from Arthrobacter globiformis (AGAO) has been determined. We have shown that the 6e- oxidation of tyrosine to topa quinone (TPQ) consumes 2 mol of O2 and produces 1 mol of H2O2/mol of TPQ formed. The rate of H2O2 production is first-order (kobs = 1.0 +/- 0.2 min-1), a rate only slightly lower than the rate of TPQ formation directly determined previously (kobs = 1.5 +/- 0.2 min-1). This gives the following net reaction stoichiometry for TPQ biogenesis: E-Tyr + 2O2 --> E-TPQ + H2O2. This stoichiometry is in agreement with recently proposed mechanisms for TPQ biogenesis, and rules out several possible alternatives.

UI	MeSH Term	Description	Entries
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
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D004295	Dihydroxyphenylalanine	A beta-hydroxylated derivative of phenylalanine. The D-form of dihydroxyphenylalanine has less physiologic activity than the L-form and is commonly used experimentally to determine whether the pharmacological effects of LEVODOPA are stereospecific.	Dopa,3,4-Dihydroxyphenylalanine,3-Hydroxy-DL-tyrosine,Dihydroxyphenylalanine Hydrochloride, (2:1),beta-Hydroxytyrosine,3 Hydroxy DL tyrosine,3,4 Dihydroxyphenylalanine,beta Hydroxytyrosine
D006631	Amine Oxidase (Copper-Containing)	A group of enzymes including those oxidizing primary monoamines, diamines, and histamine. They are copper proteins, and, as their action depends on a carbonyl group, they are sensitive to inhibition by semicarbazide.	Diamine Oxidase,Histaminase,Amine Oxidase, Copper-Containing,Copper Amine Oxidase,Diaminobenzidine Oxidase,Semicarbazide-Sensitive Amine Oxidase,Xylylene Diamine Oxidase,Amine Oxidase, Copper,Amine Oxidase, Copper Containing,Amine Oxidase, Semicarbazide-Sensitive,Copper-Containing Amine Oxidase,Diamine Oxidase, Xylylene,Oxidase, Copper Amine,Oxidase, Copper-Containing Amine,Oxidase, Diamine,Oxidase, Diaminobenzidine,Oxidase, Semicarbazide-Sensitive Amine,Oxidase, Xylylene Diamine,Semicarbazide Sensitive Amine Oxidase
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
D001173	Arthrobacter	A genus of asporogenous bacteria isolated from soil that displays a distinctive rod-coccus growth cycle.
D013056	Spectrophotometry, Ultraviolet	Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Ultraviolet Spectrophotometry
D019281	Dimerization	The process by which two molecules of the same chemical composition form a condensation product or polymer.	Dimerizations