Proteolytic Activities of Suparen and Rennilase on Buffalo, Cow, and Goat Whole Casein and β-Casein

The proteolytic specificity and activity of Mucor miehei protease (Rennilase) and Endothia parasitica protease (Suparen) on buffalo, cow, and goat whole casein and β-casein (CN) were studied by analyzing the degradation products. The results suggest that Rennilase hydrolyzes casein of the three species in a manner similar to that of chymosin, resulting in the formation of αs1-I and β-I, -II, -III as initial degradation fragments of αs1- and β-CN. αs1-I was also the initial breakdown product of αs1-CN by Suparen. Contrary to Rennilase, Suparen showed a higher affinity toward β-CN and hydrolyzes β-CN, giving rise to degradation products characterized by mobility lower than that of β-CN. Increasing NaCl concentration (>3%) reduced the proteolysis of β-CN of the three species by Rennilase but not by Suparen. The hydrolysis of αs1-CN and αs1-I by the two enzymes was enhanced in the presence of NaCl. Keywords: Proteolysis; Suparen; Rennilase; buffalo, cow, goat caseins