Molecular forms of human-liver arginase

Abstract

The chromatography of liver homogenates and purified preparations of human-liver arginase (l-arginine ureohydrolase, EC 3.5.3.1) on CM-cellulose separates two protein fractions with arginase activity. On rechromatography, each of these fractions appears homogeneous and retains its adsorption-elution characteristics.

Both arginase fractions have similar properties as far as their affinities for substrates, pH optima and thermal inactivation are concerned. However, they differ in their pH stabilities and in their inhibition by ornithine and canavanine.