Urate oxidase from the rust Puccinia recondita is a heterotetramer with two different-sized monomers

• Published in: Current microbiology 2002-04, Vol.44 (4), p.257-261
• Main Authors: AGUILAR, Miguel, MONTALBINI, Paolo, PINEDA, Manuel
• Format: Article
• Language: English
• Subjects: Bacteriology; Basidiomycota; Basidiomycota - enzymology; Biological and medical sciences; chemistry; Enzyme Inhibitors; Enzyme Inhibitors - pharmacology; Enzymes; enzymology; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; isolation & purification; metabolism; Metabolism. Enzymes; Microbiology; Molecular Weight; oxidoreductases; pharmacology; physicochemical properties; Puccinia recondita; Urate Oxidase; Urate Oxidase - chemistry; Urate Oxidase - isolation & purification; Urate Oxidase - metabolism; Uric Acid; Uric Acid - metabolism; Xanthine; Xanthine - pharmacology
• ISSN: 0343-8651; 1432-0991
• DOI: 10.1007/s00284-001-0101-x

Uricase (urate: oxygen oxidoreductase; EC 1.7.3.3) from the rust Puccinia recondita was purified to electrophoretic homogeneity. Preparations with a specific activity of 8.4 U/mg were used for characterization of the enzyme, which showed a strong similarity to other plant and fungal urate oxidases. The enzyme had a pH optimum of 9.0, a K(m) of 35 microM for urate, and it was inhibited only by oxonate and xanthine. A molecular mass of 152 kDa was estimated for the native protein. SDS-PAGE analysis revealed a striking difference to most urate oxidases, since two different-sized subunits were detected. These results suggest that P. recondita uricase is a tetramer with two types of subunits.