Purification and characterization of xanthine oxidase from livers of vitamin E deficient rabbits

Xanthine oxidase which increases in activity during vitamin E deficiency was purified from livers of deficient rabbits. The procedure incorporates preparative sucrose gradient centrifugation and yields a homogeneous preparation on acrylamide gel electrophoresis. The purified enzyme exhibits a pH optimum of 8.1 and a Km value of 22 muM. Gel filtration chromatography gave the molecular weight of 280 000. Acrylamide gel electrophoresis in the presence of sodium dodecylsulphate reveals two types of subunits of molecular weights 52 000 and 99 000.