Not available outside of the UK & Ireland.

Analysis Note

Protein determined by biuret

Biochem/physiol Actions

Although xanthine oxidase is found widely distributed in multiple tissues, it is highly expressed in endothelial and epithelial cells. Its expression was also increased in infected tissues where it was shown to have an anti-microbial effect due to its ability to generate reactive oxygen species.

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.

General description

Formerly E.C. 1.1.3.22

Physical form

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

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.