Characteristics of tributyroylglycerol hydrolysis mediated by a 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 degrees 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.