Characteristics of Tributyroylglycerol Hydrolysis Mediated by Partially Purified Lamb Pregastric Lipase

A partially purified pregastric lipase from lambs was used as a catalyst for the hydrolysis of tributyroylglycerol. The reaction was followed by pH-stat autotitration of the released butyric acid. Integral values for pH and temperature were selected for determination of full Michaelis-Menten plots, and a kinetic surface was derived to characterize the activity of the enzyme preparation over a wide combination of these conditions. This surface enclosed a region of maximum activity centered on optimal pH (pH 6.4) and temperature (43°C), although optima were not sharply delineated. The activity in the surrounding region was generally high, and the value of the Michaelis-Menten constant was < 0.2 mM, indicating that tributyroylglycerol was generally a highly favored substrate.