Purification and Properties of Porcine Gastricsin

Abstract

Abstract The proteolytic enzyme, gastricsin, has been isolated from an acidified extract of porcine gastric mucosa. The purification procedure consists of ammonium sulfate precipitation followed by chromatography on columns of Amberlite CG-50 and Sephadex G-75. The enzyme preparation was found to be homogeneous on ultracentrifugation and electrophoresis. The enzymic properties of porcine gastricsin, including optimal pH, hydrolysis of synthetic and protein substrates, milk-clotting activity, and stability in an alkaline solution, were found to be similar to those of the human enzyme. The molecular weight was found to be 32,500. The amino acid composition of porcine gastricsin was similar to that of human gastricsin and differed significantly from those of human and porcine pepsin.