Investigations on biochemical properties of milk-clotting enzymes

The properties of proteolytic enzymes produces from calf maws and from an Ascomycete were studied. Both milk-clotting proteases have their optimum activity at pH 5.2 and 45 degrees C. The microbiological rennin has a second maximum activity at pH 3.5 and 55 degrees C. Temperatures above 55 degrees C cause a rapid decrease of activity. The behaviour of enzyme activity is similar with varying substrate and enzyme concentrations. However, increasing amounts of enzyme in ratio to the substrate lead to reaction rates of the calf rennin differing clearly from that of the microbiological rennet complex.