Lamb Pregastric Lipase Activity: Catalyzed Hydrolysis of Dibutyryl-1,2(3)-Propanediols and Butyryl-1(2)-Propanol and Inhibition of the Catalyzed Hydrolysis of Tributyrylglycerol in the Presence of EDTA, LiCl, NaCl and Ethanol

Abstract

Partially purified lamb pregastric lipase, LPGL, isolated from the tongue and epiglottal region of lamb, was used to catalyze the hydrolysis of tributyrylglycerol, the dibutyryl esters of propanediol and the butyryl esters of propanol at pH 6.5, 35°C. The relative rates of hydrolysis for tributyrylglycerol: dibutyryl-1,2-propanediol: dibutyryl-1,3-propanediol: butyryl-1-propanol: butyryl-2-propanol were 100: 35.4: 12.5: 4.1: 1.1, respectively. Monohydrolysis stoichiometry was observed for tributyrylglycerol and the diesters with saturation kinetics. In contrast, hydrolysis of the monoesters was first-order in substrate. The catalyzed hydrolysis of tributyrylglycerol was ~20% inhibited in the presence of 100 mM EDTA, 10% and 60% in the presence of 1 M NaCl and LiCl, respectively, and ~30% in 10% v/v ethanol.