Abstract
Milk-clotting enzymes may be classified into two groups according to their degradation pattern of αs1-casein in solution at pH 6.0. On the one hand, calf chymosin and Mucor miehei enzyme produced only one degradation product corresponding to αs1-I under the conditions we employed. On the other hand, Irpex lacteus and Endothia parasitica enzymes produced several degradation products accompanied by a product corresponding to αs1-I. The Irpex milk-clotting enzyme hydrolyzed αs1-casein at the positions of His(8)-Gln(9), Phe(23)-Phe(24), Lys(103)-Tyr(104), and Phe(153)-Tyr(154). Irpex enzyme has only one common cleaving site with calf chymosin, that is, the Phe(23)-Phe(24) bond of αs1-casein.
