Lysosomal acid deoxyribonuclease from vervet monkey livers—I: Purification and physico-chemical characterization

Abstract

1. 1. Acid DNase from monkey liver lysosomes was purified to homogeneity by salt extraction of lysosomal membranes at pH 3.8; (NH 4) 2SO 4 fractionation; low salt precipitation; SP-C 50 and G-150 Sephadex chromatography; and polyacrylamide gel electrophoresis. 2. 2. The pH for optimum activity was dual in character with a labile optimum at pH 3.8 and a less active but stable one at pH 4.2 3. 3. The estimated molecular weight was 40 K and the p l was 4.4. 4. 4. Inorganic ions such as Ca 2+, Mg 2+, Mn 2+ and SO 4 2− were more than 80% inhibitory at 10-mM levels. Fe 3+ ions were 80% inhibitory at 0.1-mM levels. 15. Nad at 100 mM is essential for activity but becomes 100% inhibitory above 200 mM.