Coenzyme of Kidney Phosphatase

Abstract

IN previous communications¹ we advanced a hypothesis supporting the nucleotide nature of kidney phosphatase. Kutscher and Schreier² also consider phosphatases as metal proteins, and they attribute the loss in activity which they display on dialysis not only to the elimination of magnesium, but also to the separation of another substance which Kutscher and Sieg³ designate as choline pyro-phosphate. In their turn, Akamatsu and Kobayashi⁴ regard histidine as a coenzyme. Recently, however, investigating intestinal phosphatase preparations purified by paper electrophoresis, Roche considers⁵, in view of the results obtained in his analyses, that the hypotheses advanced on the nature of cophos-phatase (nucleotide, choline pyrophosphata or histidine) are scarcely probable.