Purification and properties of rennin-like enzyme from Absidia cylindrospora

Abstract

Summary Purification of the milk-clotting enzyme preparation from Absidia cylindrospora by DEAE-cellulose column chromatography afforded a rennin-like enzyme component that showed no proteolytic activity. The enzyme activity was maximum at 52.5 °C and pH 6.7. Under these conditions the enzyme clotted 1,200 times its own weight of skim milk within 4 min. In absence of substrate the enzyme was more stable at pH 4.05. Ca2+, Ba2+, Fe2+, Mg2+, cysteine-HCl, ascorbic acid, and reduced glutathione had stimulating effects on enzyme activity. Sodium lauryl sulphate, p-chloromercuribenzoate, and KCN had partial inhibitory effects on the enzyme.