Biomaterial Database

A kinetic study of hypoxanthine oxidation by milk xanthine oxidase. 1988

J Escribano, and F Garcia-Canovas, and F Garcia-Carmona

Departamento de Bioquimica, Universidad de Murcia, Spain.

The course of the reaction sequence hypoxanthine----xanthine----uric acid catalysed by xanthine:oxygen oxidoreductase from milk was investigated on the basis of u.v. spectra taken during the course of hypoxanthine and xanthine oxidations. It was found that xanthine accumulated in the reaction mixture when hypoxanthine was used as a substrate. The time course of the concentrations of hypoxanthine, xanthine intermediate and uric acid product was simulated numerically. The mathematical model takes into account the competition of substrate, intermediate and product and the accumulation of the intermediate at the enzyme. This type of analysis permits the kinetic parameters of the enzyme for hypoxanthine and xanthine to be obtained.

UI	MeSH Term	Description	Entries
D007042	Hypoxanthines	Purine bases related to hypoxanthine, an intermediate product of uric acid synthesis and a breakdown product of adenine catabolism.
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008892	Milk	The off-white liquid secreted by the mammary glands of humans and other mammals. It contains proteins, sugar, lipids, vitamins, and minerals.	Cow Milk,Cow's Milk,Milk, Cow,Milk, Cow's
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
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
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
D014527	Uric Acid	An oxidation product, via XANTHINE OXIDASE, of oxypurines such as XANTHINE and HYPOXANTHINE. It is the final oxidation product of purine catabolism in humans and primates, whereas in most other mammals URATE OXIDASE further oxidizes it to ALLANTOIN.	2,6,8-Trihydroxypurine,Ammonium Acid Urate,Monosodium Urate,Monosodium Urate Monohydrate,Potassium Urate,Sodium Acid Urate,Sodium Acid Urate Monohydrate,Sodium Urate,Sodium Urate Monohydrate,Trioxopurine,Urate,Acid Urate, Ammonium,Acid Urate, Sodium,Acid, Uric,Monohydrate, Monosodium Urate,Monohydrate, Sodium Urate,Urate Monohydrate, Monosodium,Urate Monohydrate, Sodium,Urate, Ammonium Acid,Urate, Monosodium,Urate, Potassium,Urate, Sodium,Urate, Sodium Acid
D014969	Xanthine Oxidase	An iron-molybdenum flavoprotein containing FLAVIN-ADENINE DINUCLEOTIDE that oxidizes hypoxanthine, some other purines and pterins, and aldehydes. Deficiency of the enzyme, an autosomal recessive trait, causes xanthinuria.	Hypoxanthine Oxidase,Hypoxanthine Dehydrogenase,Hypoxanthine-Xanthine Oxidase,Purine-Xanthine Oxidase,Dehydrogenase, Hypoxanthine,Hypoxanthine Xanthine Oxidase,Oxidase, Hypoxanthine,Oxidase, Hypoxanthine-Xanthine,Oxidase, Purine-Xanthine,Oxidase, Xanthine,Purine Xanthine Oxidase
D014970	Xanthines	Purine bases found in body tissues and fluids and in some plants.
D019271	Hypoxanthine	A purine and a reaction intermediate in the metabolism of adenosine and in the formation of nucleic acids by the salvage pathway.