Comparism of xanthine oxidase activities in cow and goat milks

The activities of xanthine oxidase were studied in cow and goat milks. The optimum temperature and pH values were 10 oC and 7.5; and 20 oC and 7.2 – 7.4 for cow and goat milk samples respectively. The substrate effect on xanthine oxidase from both milk samples followed the popular Michealis Menten's (Km) equation. The Km and V max were 0.86 x 10-2 M and 3.7 Msec-1 and 4.36 x 10-2 M and 2.0 Msec-1. The work concludes that xanthine oxidase from cow and goat milk differs both in their basic characteristics and in the kinetic activities. Key words: xanthine oxidase. Milk, kinetic parameters Biokemistri Vol.17(1) 2005: 1-