title: Urate oxidase from the rust Puccinia recondita is a heterotetramer with two different-sized monomers.
abstract: 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.
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba, Campus Rabanales, Edificio C-6, 1 Planta, 14071-Córdoba, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Aguilar
authors.forename: Paolo
authors.initials: P
authors.lastname: Montalbini
authors.forename: Manuel
authors.initials: M
authors.lastname: Pineda
mesh_terms: D001487:Basidiomycota / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D014503:Urate Oxidase / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D014527:Uric Acid / Q000378:metabolism; D019820:Xanthine / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D019820:Xanthine; D014527:Uric Acid; D014503:Urate Oxidase