A lipid-coated lipase as an efficient hydrolytic catalyst in the two-phaseaqueous-organic system

A lipid-coated lipase has been known to be soluble in organic solvents and act as an efficient esterification catalyst in the dry organic solvent. It was also found to act as an efficient hydrolytic catalyst for lipophilic es ters in the two-phase aqueous-organic system. Both the lipid-coated lipase and substrates are solubilized in the organic phase and the hydrolysis occu rs with water molecules from the aqueous phase. Therefore, the reaction was 40-100 times faster than that of the native lipase, in which the enzyme an d substrate exist separately in the aqueous and organic phase, respectively , and the reaction proceeded at the interface. The hydrolysis rates for the lipid-coated lipase were not affected by the aqueous pH and agitation spee d of the two-phase. Enzymatic activity of the lipid-coated lipase was compa red with that of the poly(ethylene glycol)-grafted lipase. Michaelis-Menten kinetics in the two-phase reactions was also studied. (C) 2001 John Wiley & Sons, Inc.