On the Activation of Pancreatic Lipase by Calcium Chloride at Varying pH

Abstract

Summary. The activating influence of calcium chloride on the hydrolysis by pancreatic lipase of several saturated triglycerides and triolein has been investigated at different pH. 1. With increasing number of carbon atoms in the fatty acids of the triglycerides the optimum pH for pancreatic lipase is displaced from 7 to 8.8. 2. Addition of CaCl 2 does not alter the optimum pH for the enzymatic activity towards a triglyceride. 3. CaCl 2 activates the hydrolysis of all triglycerides investigated in homogeneous as well as in heterogeneous systems and both in alkaline and acid medium. 4. In the presence of CaCl 2 the pH‐activity range for the higher saturated triglycerides is widened one pH unit on the acid side. 5. The higher free fatty acids are supposed to depress the hydrolysis by pancreatic lipase in a high degree, and the pronounced activation by CaCl 2 in experiments with higher triglycerides is explained by the removal of free acids as insoluble calcium soaps. 6. The experiments do not support WILLSTÄTTER'S theory of the activation of lipase by formation of complex adsorbates.