ALKALINE-PHOSPHATASES FROM HENS EGG-YOLK, LIVER, BLOOD PLASM AND INTESTINAL-MUCOSA - AFFINITY CHROMATOGRAPHIC PURIFICATION AND COMPARISON

1. 1. Alkaline phosphatases from hen's egg yolk, liver, blood plasm, and intestinal mucosa were purified with, as main purification step, affinity chromatography on 4-(p-amino-phenylazo)-phenylarsonic acid-epoxy-Sepharose 4B. Specific activities up to 50 U/mg were obtained. 2. 2. Yolk alkaline phosphatase is composed of two identical inactive subunits with Mg 68,800 ± 1700. The active enzyme monomer has a Mg 150,400 ± 2100. Comparable values were obtained for the predominant liver and blood plasm enzymes. The active monomer from intestinal mucosa has a MR 120,000. 3. 3. All alkaline phosphatases are mixtures of enzyme forms, differing in glycoprotein content and/or amount of charged groups. 4. 4. The concept that yolk proteins are synthesized in the liver, and transported through the blood plasm to the growing egg yolk, is not invalidated. The heterogeneity of the blood plasm alkaline phosphatase originates likely from the presence of liver, intestinal mucosa, and bone alkaline phosphatases. © 1979.