Enhancing enantioselectivity of a lipid-coated lipase via imprinting methods for esterification in organic solvents

Abstract

Lipase OF from Candida showed only low enantioselectivity for esterification of ( R)- or S-1-phenylethanol with lauric acid ( v R v S = 5.5 ). However, when lipase OF was imprinted with a substrate analogue such as ( R)-1-phenylethanol and then coated with synthetic glycolipid molecules, the imprinted lipid-coated lipase shows a large enantioselectivity for the esterification in anhydrous isooctane ( v R v S = 77 ). When the native lipase OF was imprinted by the same procedure, the enantioselectivity hardly changed. The lipid coating was important to keep the imprinted structure as well as to solubilize enzymes in organic solvents. The improved enantioselectivity was confirmed from Michaelis-Menten kinetics as due to the intramolecular catalytic reaction and not the substrate binding process. The improved enantioselectivity reverts to the original non-imprinted value if kept in the organic solvents at high temperatures for days.