Xanthine Oxidase (XOD) is a metal flavoprotein. It has flavin adenine dinucleotide (FAD), molybdenum and iron in the ratio 2:2:8. This homodimer has a molecule weight of 290kDa. It is a member of the molybdenum-protein family. This enzyme consists of two separated substrate-binding sites.
Formerly E.C. 126.96.36.199
Xanthine Oxidase from bovine milk has been used:
- in the preparation of xanthine oxidase (XO) solution for 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide (DEPMPO)-spin trapping assay
- in in vitro XO assay for screening Vietnamese medicinal plants for XO inhibitory activity
- as a standard to determine XO activity
- as a standard to test the synergistic effect of docosahexaenoic acid (DHA)
5, 25 units in serum bottle
Hydroxylation of hypoxanthine to xanthine and xanthine to uric acid is catalyzed by xanthinebb oxidase (XO) enzyme.
Xanthine oxidase is a molybdenum-containing enzyme that is found in the cytosol, and may be strongly inhibited by flavonoids. It plays a vital role in the metabolism of some drugs, as well as purines and pyrimidines. It is also known to be a biological source of reactive oxygen species.
Xanthine oxidase was shown to be involved in the reduction of cytochrome c by the generation of superoxide anions following the oxidation of xanthine. These free radicals are responsible for reducing cytochrome c.
Definição da unidade
One unit will convert 1.0 μmole of xanthine to uric acid per min at pH 7.5 at 25 °C. Approx. 50% of the activity is obtained with hypoxanthine as substrate.
Suspension in 2.3 M (NH4)2SO4 containing 1 mM sodium salicylate
Nota de análise
Protein determined by biuret