KINETICS OF LIPASE-CATALYZED HYDROLYSIS OF LIPIDS IN BIPHASIC ORGANIC AQUEOUS SYSTEMS

A kinetic model has been proposed which is applicable to the hydrolysis of lipids by lipases in biphasic organic-aqueous systems. An analytical rate equation, based on the interfacial substrate concentration, was derived and confirmed from previous experimental data. The equation may be reduced further to the Michaelis-Menten form for the system by adding a water-immiscible organic solvent (or using hydrophobic particles but for hydrophilic substrates). The reduced form cannot be obtained when the organic phase only contains the hydrophobic substrate. Moreover, the concept of substrate inhibition and certain conflicting expressions for the apparent maximum velocity and Michaelis-Menten constant, that previous investigators claimed, have been clarified in the present study.