Biomaterial Database

The nitrate reductase activity of milk xanthine oxidase. 1985

N S Sergeev, and L I Ananiadi, and N P L'vov, and W L Kretovich

Milk xanthine oxidase oxidizes xanthine at pH 9.6 and reduces nitrates at pH 5.2. It is shown that the nitrate reductase activity requires molybdenum and sulfur-containing sites in the enzyme, whereas oxidation of xanthine also requires iron-containing sites and FAD. As the pH changes from 5.2 to 9.6, the conformation of the enzyme molecule is modified as demonstrated by changes in the absorption, fluorescence, and circular dichroism spectra. When the enzyme is treated with dithioerythritol, it may pass from the oxidase to the dehydrogenase form with a marked increase in the nitrate reductase activity.

UI	MeSH Term	Description	Entries
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
D009565	Nitrate Reductases	Oxidoreductases that are specific for the reduction of NITRATES.	Reductases, Nitrate
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D002122	Calcium Chloride	A salt used to replenish calcium levels, as an acid-producing diuretic, and as an antidote for magnesium poisoning.	Calcium Chloride Dihydrate,Calcium Chloride, Anhydrous
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D002729	Chloromercuribenzoates	Chloride and mercury-containing derivatives of benzoic acid.
D004226	Dithioerythritol	A compound that, along with its isomer, Cleland's reagent (DITHIOTHREITOL), is used for the protection of sulfhydryl groups against oxidation to disulfides and for the reduction of disulfides to sulfhydryl groups.	2,3-Dihydroxy-1,4-dithiolbutane,Dithioerythreitol
D005182	Flavin-Adenine Dinucleotide	A condensation product of riboflavin and adenosine diphosphate. The coenzyme of various aerobic dehydrogenases, e.g., D-amino acid oxidase and L-amino acid oxidase. (Lehninger, Principles of Biochemistry, 1982, p972)	FAD,Flavitan,Dinucleotide, Flavin-Adenine,Flavin Adenine Dinucleotide
D006358	Hot Temperature	Presence of warmth or heat or a temperature notably higher than an accustomed norm.	Heat,Hot Temperatures,Temperature, Hot,Temperatures, Hot
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations