Kinetic study of the enantioselective hydrolysis of a meso-diester using Pig Liver Esterase

A kinetic study of the hydrolysis of the diester dimethyl cis-cyclohex-4-en e-1,2-dicarboxylate, to the (1S,2R)-monoester, catalysed by the enzyme Pig Liver Esterase (PLE) was performed. The effects of the most relevant parame ters that influence the enzymatic conversion were studied, such as pH, temp erature and concentration of substrate and reaction products. It was conclu ded that the pH at which the enzyme exhibits a maximum activity is pH 7. At 25 degrees C PLE presents a better long-term stability and enantioselectiv ity than at higher temperatures, although the reaction rate is slower. The kinetic results obtained are well described by the Michaelis-Menten equatio n, although a slight deviation to this model was observed for low substrate concentrations. Methanol, a co-product of the enzymatic hydrolysis, was fo und to act as a non-competitive inhibitor of the reaction. The Michaelis-Me nten parameters were determined and a comprehensive kinetic model, which al ready accounts for methanol inhibition, is presented. (C) 2000 Society of C hemical Industry.