[Urate oxidase from pig liver: biochemical and immunological properties]

A highly purified uratoxidase was isolated from the pig liver. The sedimentation coefficient of the enzyme was 6.96 S and the molecular weight was 122,000 +/- 4,000. The enzyme was a tetramer consisting of subunits with a molecular weight of 31,600 +/- 2,500. Uratoxidase showed high substrate specificity with 0.05 M borate buffer, pH 8.5. During competitive inhibition 8-azaxanthine (Ki = 3.1 X 10(-7) M) produced the strongest inhibitory effect as compared with other purine compounds. N-chloromercuric benzoate and ascorbic acid also inhibited strongly uratoxidase activity. EDTA-Na2, methyl ester of n-oxybenzoic acid, phenyl methyl sulphonyl fluoride and cystein did not influence the enzyme activity.