9876. Uricase

Nomenclature

CAS number: 9002-12-4
Urate oxidase; uric oxidase; urico-oxidase; uriKoxidase.

Description and references

An enzyme responsible for the oxidative scission of the purine skeleton, and therefore of key importance to the catabolism of nitrogenous compds in general in organisms that do not eliminate intact uric acid or some other purine. All mammals except the primates (including man) are uricolytic organisms. Porcine liver or bovine kidney is the starting material for various purified prepns of uricase. Isoln from porcine liver: Holmberg, Biochem. J. 33, 1901 (1939); Miller et al., J. Biol. Chem. 216, 625 (1955); Robbins, Grant, US 2878161 (1959 to Armour). Review: Mahler, “Uricase” in The Enzymes vol. 8, P. D. Boyer et al., Eds. (Academic Press, New York, 1963) pp 285-296.

Properties

Pale, brownish-green crystals or shiny, transparent, striated plates. Practically insol in water. Slightly sol in buffered alkali solns. Solns at pH 7.5-10.5 are relatively stable. Shows unusually high absorption in the region of 330-350 nm (for highly purified uricase: A1%276 = 11.3, A1%330 = 2.0, both in 1% Na2CO3; A280/A330 = 5.6). Isoelec. pt. pH 6.3. Copper content of the enzyme (specific activity 120-125) equals ≈0.56 mg/g of enzyme protein. There appears to be a satisfactory correlation between copper content and activity of the purified enzyme. The enzyme is sensitive to cyanide ion; the presence of 104M KCN inhibits its activity.

Use

In the determination of serum and urine uric acid.