Acid Angiotensinase, Renin, and Acid Adenosine Triphosphatase in Rat Kidney Lysosomes

Abstract

1. Kidney angiotensinases are located in two kinds of subcellular fraction-lysosomal and microsomal. Lysosomal angiotensinase is active at an acid pH and inhibited by DFP, suggesting a relationship to plasma acid angiotensinase. Most of the activity was released from the particles by freezing and thawing. The microsomal enzyme is active near neutral pH, activated by calcium ion and inhibited by EDTA . 2. About 70 per cent of renin activity was released from the subcellular particles in lysosomal fraction of rat kidney by freeze-thaw method. It revealed only one peak on either Sephadex G-100 gel filtration or DEAE-cellulose column chromatography. The molecular weight of renin was calculated as 40, 000-50, 000. 3. At least three components of acid ATPase were found in lysosomal fraction of rat kidney by DEAE-cellulose column chromatography.