FURTHER CHARACTERIZATION AND KINETIC POROMETER DETERMINATION OF A MILK-CLOTTING PROTEASE FROM MUCOR BACILLIFORMIS

Further characterization of an aspartyl protease from Mucor bacillifor mis with milk-clotting activity was performed. An extinction coefficie nt, epsilon(278 cm) = 1.61 ml/mg/cm, a molecular mass of 35,400 Da and a pI of 5.2 were determined. Proteolytic activity and kinetic paramet ers were evaluated by using the hexapeptide Leu-Ser-pNO(2)-Phe-Nle-Ala -Leu-OMe as the substrate. The effect of pH and temperature on peptide cleavage, as well as protease heat stability, was determined. Such pr operties, taken as a whole, indicate that the M. bacilliformis proteas e can be considered a potential substitute for bovine chymosin in chee se manufacture.