Abstract
Alkaline phosphatase (E.C. 3. 1. 3. 1) was extracted from human small intestine by a modified Morton's butanol method and was purified by ammonium sulfate precipitation, and chromatography over diethylaminoethyl (DEAE)-cellulose, carboxymethyl (CM)-collulose, and Sephadex G-200. The homogeneity of the purified enzyme was demon-strated by disc electrophoresis and immunoelectrophoresis. The purified enzyme was activated by MgCl2, but inhibited by HgCl2 and CdCl2. Inactive apoenzyme, prepared by incubation with 2×10-4M ethylenediaminetetraacetic acid (EDTA) at pH 7.4, is optimally reactivated by Zn2+. The heat activation for hydrolysis of p-nitrophenyl phosphate was calculated as 9000 cal/mole.
