Vitamin E deficiency: immunochemical evidence for increased accumulation of liver xanthine oxidase.

Xanthine oxidase (EC 1.2.3.2) activity increases in liver of rabbits deficient in vitamin E. Immunochemical titration of the enzyme demonstrates that the elevation of activity is due to an increased accumulation of the enzyme protein rather than activation of preexisting enzyme molecules. Immunochemically, xanthine oxidase from deficient animals is indistinguishable from the enzyme from control animals. Incorporation of labeled leucine into immunoprecipitable xanthine oxidase is enhanced in vitamin E-deficient animals. This enhancement is interpreted as indicating that the accumulation of xanthine oxidase molecules reflects an accelerated de novo synthesis of the enzyme.