X4500

Xanthine Oxidase from bovine milk

Grade III, ammonium sulfate suspension, ≥0.8 units/mg protein

• Synonym(s): Schardinger enzyme, XnOx, hypoxanthine oxidase, XOD, Xanthine:oxygen oxidoreductase
• CAS Number: 9002-17-9
• Enzyme Commission number: 1.17.3.2.
• EC Number: 232-657-6
• MDL number: MFCD00082145
• UNSPSC Code: 12352204
• NACRES: NA.54

Properties

• biological source: bovine milk
• type: Grade III
• form: ammonium sulfate suspension
• specific activity: ≥0.8 units/mg protein
• technique(s): inhibition assay: suitable
• color: faint brown to dark brown
• UniProt accession no.: A0A3Q1LW91; A0A3Q1MM92; A0A3S5ZPW7
• foreign activity: uricase ≤0.1%
• storage temp.: 2-8°C

Description

General description

Research area: Cell Cycle

Xanthine Oxidase (XO) belongs to the class of complex metalloflavoproteins. It is produced by oxidation of sulfhydryl residues or by proteolysis of xanthine dehydrogenase (XDH). XO is characterized with two flavin molecules (FAD), two molybdenum atoms, and eight iron atoms bound per enzymatic unit.

Formerly E.C. 1.1.3.22

Application

Xanthine Oxidase from bovine milk has been used:

• as a source for superoxide generation
• for the degradation of hypoxanthine
• for the detection of reactive oxygen species (ROS) in lipid model by electron spin resonance (ESR) spin trap method
• as a constituent of assay mixture in xanthine oxidase inhibition assay

Biochem/physiol Actions

Xanthine Oxidase (XO)catalyzes the hydroxylation of hypoxanthine to xanthine and xanthine to uric acid. Xanthine oxidase activity is inhibited by folic acid. [7] and various other inhibitors including 3,4-Dihydroxy-5-nitrobenzaldehyde (DHNB), febuxostat and allopurinol. XO and xanthine dehydrogenase (XDH) plays a vital role in the last two steps in the formation of urate. Elevated levels of XO has been observed in the serum of chronic liver disease patients. Therefore, XO can be used as a biomarker for the detection of liver disease.

Xanthine oxidase activity is inhibited by folic acid.

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.

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, 10 mM sodium phosphate buffer, pH 7.8, containing 1 mM EDTA and 1 mM sodium salicylate

Preparation Note

Chromatographically purified

Storage and Stability

Tightly closed. Dry. Keep locked up or in an area accessible only to qualified or authorized
persons

Analysis Note

Protein determined by biuret

Safety Information

• Pictograms: GHS08
• Signal Word: Danger
• Hazard Statements: H334
• Precautionary Statements: P261 - P284 - P304 + P340 + P312 - P501
• 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