PRESENCE OF TRIMETAPHOSPHATASE IN THE INTESTINAL MUCOSA AND PROPERTIES OF THE ENZYME

Abstract

Trimetaphosphatase was shown to be present in intestine. Enzyme extracted from rat duodenum had optimum activity at pH 4, and was not activated by divalent cations. There was no inhibition by Mg⁺⁺, weak inhibition by Ca⁺⁺, Zn⁺⁺, Co⁺⁺, and Mn⁺⁺, and strong inhibition by VO⁺⁺ and possibly by Be⁺⁺, Fe⁺⁺, and Cu⁺⁺. The enzyme was relatively resistant to organic solvents, formaldehyde, and KCN, and readily inactivated by NaF and KSCN. The bulk of the enzyme was bound to a sedimentable fraction, the remainder was soluble in water. Histochemical localization in the rat was in the lamina propria mucosae of the entire small intestine. In the mouse the enzyme was localized in the cytoplasm of the mucous epithelium of the small intestine.