BIOCHEMICAL STUDIES OF XANTHINE OXIDASE IN MILK

Abstract

This work has been carried out to prepare and purify milk xanthine oxdiase (XO). Milk XO was separated and purified by gel chromatographic methods. The elution profile recorded two peaks, dimeric and monomeric XO respectively. The inhibitory effect of folic acid, sod. ascorbate, sod. bisulfite on the activity of XO was monitored by incubating the enzyme with different concentrations of these inhibitors. Moreover the effect of marin and myricetin as flavonoids on the XO activity were also studied. The interactions of milk XO with some chemical modifiers such as N-phenylmaleimide, p-toluenesulfonyl chloride, and 2- mercaptobenzimidazole were examined spectrophotometricaUy.