Comparison of Properties of Human Intestinal and Placental Alkaline Phosphatase

Abstract

Enzymic properties of purified alkaline phosphatases (ortho-phosphoric monoester phosphohydrolase, E. C. 3. 1. 3. 1) from human small intestinal mucosa and human placenta were compared. Intestinal alkaline phosphatase had similar properties to those of placental alkaline phosphatase with respect to inhibition by L-phenylalanine, isoelectric point, pH stability, optimum pH, and Michaelis constant. However, difference in enzymic properties was found with respect to the molecular weight, heat stability, and the degree of inhibition by phosphate ion.