Purification and characterization of extracellular Pseudomonas aeruginosa urate oxidase enzyme

Urate oxidase (uricase) was isolated and purified from Pseudomonas aeruginosa to apparent homogeneity using ammonium sulphate precipitation followed by ion exchange and gel filtration chromatography. The specific activity of the purified uricase enzyme was found to be 636.36 with the use of uric acid as a substrate. The purified uricase enzyme is a monomeric protein with molecular weight of 64 kilodaltons. The optimal pH and temperature of the purified enzyme is 9.0 and 30 degrees C, respectively. The effect of some metal ions was studied. Sulphate forms of Fe+2, Zn+2 and Co+2 inhibit the uricolytic activity whereas; NaCl and CaCl2 enhance the enzyme activity. Moreover, the purified enzyme is inhibited by EDTA and KCN.