632. Reactivation of milk phosphatase following heat treatment: IV. The influence of certain metallic ions

Abstract

1. Reactivation of alkaline milk phosphatase is affected by the presence of ions, Mg²⁺, Zn²⁺and Mn²⁺being activating and Cu²⁺, Ni²⁺and Co²⁺being inhibitory.2. Cu²⁺will inhibit reactivation induced by Mg²⁺, but has no effect upon Zn²⁺-induced reactivation.3. Using washed cream, either alone or in admixture with boiled whey treated with cationic resin, reactivation occurs in the presence of added Mg²⁺, but not when Zn²⁺is added.4. Experiments with EDTA. confirm that metallic ions play a part both in alkaline phosphatase activity and in reactivation.5. It is suggested that either Mg²⁺or Zn²⁺or both play a part in reactivation.