胍和脲溶液对氨基酰化酶活性和构象的影响

The effects of different concentrations of guanidine and urea on the activity and conformation of pig kidney aminoacylase in solution have been studied. The results obtained clearly show that at low concentrations of guanidine and urea, less than 2m發/L, the degree of conformationsl changes in aminoacylase molecule is approximately in parallel to that of the disapperance of enzymatic activity, and at high concentrations of guanidine and urea, 2 mol/L or more, the degree of inactivation is more than that of the conformational changes of the enzyme. Comparing this result with those obtained from creatine kinase, chymotrypsin and ribonuclease, we suggest that Zn++ in aminoacylase molecule probably contributes partially to the stabilization of the local conformation in active sites of the protein, but has little effect on the overall conformation