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Xanthine Oxidase from bovine milk

Grade I, ammonium sulfate suspension, ≥0.4 units/mg protein

XOD, Xanthine:oxygen oxidoreductase
CAS Number:
Enzyme Commission number:
EC Number:
MDL number:


Grade I

Quality Level


ammonium sulfate suspension

specific activity

≥0.4 units/mg protein

foreign activity

uricase ≤0.5%

shipped in

wet ice

storage temp.


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General description

Xanthine Oxidase (XOD) is a metal flavoprotein. It has flavin adenine dinucleotide (FAD), molybdenum and iron in the ratio 2:2:8.[1] 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.[2]
Formerly E.C.


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[3]
  • in in vitro XO assay for screening Vietnamese medicinal plants for XO inhibitory activity[4]
  • as a standard to determine XO activity[5]
  • as a standard to test the synergistic effect of docosahexaenoic acid (DHA)[6]


5, 25 units in serum bottle

Biochem/physiol Actions

Hydroxylation of hypoxanthine to xanthine and xanthine to uric acid is catalyzed by xanthinebb oxidase (XO) enzyme.[2]
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. [7]

Unit Definition

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.

Physical form

Suspension in 2.3 M (NH4)2SO4 containing 1 mM sodium salicylate

Analysis Note

Protein determined by biuret


Health hazard

Signal Word


Hazard Statements

Hazard Classifications

Resp. Sens. 1

Storage Class Code

11 - Combustible Solids



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Certificate of Analysis

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Certificate of Origin

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Technical Information

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