Abstract
Three types of proteinases contained in baker's yeast were fractionated and partially purified by chromatography on TEAE-cellulose and on DEAE-Sephadex. These enzymes were designated as proteinase A, B and C, and some properties of proteinase A and B were described.
A was similar to pepsin and “acid-proteinase” produced by various fungi, but did not hydrolyze carbobenzoxy-L-glutamyl-L-tyrosine. B had milk-clotting activity and proteolytic activity toward casein, and also esterolytic activity toward N-acetyl-L-tyrosine ethylester and α-N-benzoyl-L-arginine ethylester. This enzyme was inhibited by p-mercuribenzoate and diisopropylphosphorofluoridate.
