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X1875

Sigma-Aldrich

Xanthine Oxidase from bovine milk

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

Synonym(s):

XOD, Xanthine:oxygen oxidoreductase

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About This Item

CAS Number:
Enzyme Commission number:
1.17.3.2.
EC Number:
MDL number:
UNSPSC Code:
12352204
NACRES:
NA.54

type

Grade I

form

ammonium sulfate suspension

specific activity

≥0.4 units/mg protein

foreign activity

uricase ≤0.5%

shipped in

wet ice

storage temp.

2-8°C

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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. 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. 1.1.3.22

Application

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)

Biochem/physiol Actions

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.

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

Pictograms

Health hazard

Signal Word

Danger

Hazard Statements

Hazard Classifications

Resp. Sens. 1

Storage Class Code

11 - Combustible Solids

WGK

WGK 3

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

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Methods of Enzymatic Analysis (2012)
Antioxidant properties of propofol and erythropoietin after closed head injury in rats
Ozturk E, et al.
Progress in Neuro-Psychopharmacology & Biological Psychiatry, 29, 922-927 (2005)
Xanthine oxidase: isolation, assays of activity, and inhibition
Kostic DA, et al.
Journal of Chemistry, 2015 (2015)
Xanthine oxidase inhibitors from Archidendron clypearia (Jack.) I.C. Nielsen: Results from systematic screening of Vietnamese medicinal plants
Duong NT, et al.
Asian Pacific Journal of Tropical Medicine, 10(6), 549-556 (2017)
Kurt Warnhoff et al.
Genes & development, 35(3-4), 212-217 (2021-01-16)
The molybdenum cofactor (Moco) is a 520-Da prosthetic group that is synthesized in all domains of life. In animals, four oxidases (among them sulfite oxidase) use Moco as a prosthetic group. Moco is essential in animals; humans with mutations in

Articles

Instructions for working with enzymes supplied as ammonium sulfate suspensions

Protocols

Enzymatic Assay of Superoxide Dismutase

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