Acid phosphatases and ribonucleases from Dactylis glomerata seeds. I. Chromatographic and electrophoretic heterogeneity of the enzymes

Abstract

Acid phosphatase and ribonuclease extracted with 0.1 M sodium acetate buffer, pH 5.1 from Dactylis glomerata seeds, and partially purified by means of 70% ethanol precipitation showed electrophoretic and Chromatographic heterogeneity. After chromatography on DEAE-cellulose acid phosphatase and ribonuclease were separated into four peaks. Nonadsorbing acid phosphatase on DEAE-cellulose (peak I) was separated into four peaks on CM-cellulose. The highest activity (11 units/mg) was found in fraction b (acid phosphatase Ib). The enzyme was activated by Mg²⁺, Ca²⁺, Li⁺, Cs⁺, K⁺ ions and inhibited by Cu²⁺, Zu²⁺, F^- and Mo^-6 at optimum pH 5.0. Strong absorbing ribonuclease on DEAE-cellulose (peak IV) was further separated on G-200 Sephadex into two molecular forms: RN-asa1 and RN-ase2. Ribonuclease l, a thermolabile enzyme with specific activity 807 units/mg, showed an optimal activity at pH 4.8-5.1.