Some enzymic properties of the crystalline acid-protease of
Paecilomyces varioti Bainier TPR-220 were studies.
1. The presend acid-protease is most active at pH 3.0 at 60°C toward casein, and can also hydrolyses egg albumin, horse hemoglobin denatured with hydrochloric acid or urea, and blood fibrin.
2. This enzyme is most stable around pH 5, and when incubated at pH 3.0 and 5.0 at 55°C for four hours, it lost 95 and 45% of the activity respectively.
3. No metal ion is essential to the enzymic action, and the enzyme is inhibited by some of sulfhydryl reagents but is not a papainase.
4. The presence of Ca
++, Co
++, Cu
++, Mg
++, Mn
++, Sr
++, and Zn
++ ions prevents the heat inactivation of the enzyme at pH 5.0 and 60°C to some extent but does not at pH 3.0. EDTA shows the same action.
5. The enzyme decomposes casein into smaller fragments than pepsin does.
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