Isolation of different animal liver xanthine oxidase containing fractions and determination of kinetic parameters for xanthine
Department of Pharmaceutical Chemistry, Bombay College of Pharmacy, Kalina, Mumbai-400 098, India
K R Iyer Department of Pharmaceutical Chemistry, Bombay College of Pharmacy, Kalina, Mumbai-400 098 India E-mail: [email protected]
Xanthine oxidase activity containing fractions from rat, mouse, rabbit and guinea pig livers were obtained by heat treatment and ammonium sulfate precipitation. Xanthine oxidase activity was observed in rat and mouse liver fractions, while xanthine oxidase activity was absent in rabbit and guinea pig liver fractions. Enzyme kinetic parameters, Km and Vmax, were determined for the conversion of xanthine to uric acid by rat and mouse live fractions, by both spectrophotometric and HPLC methods. The Km values obtained by either method for both animal liver fractions were in the range of 5.32-13.8 µM.