Polyethyleneimine-MOF composite as a support for immobilization of lipase with enhanced activity in kinetic resolution

Abstract

Lipase PS from Pseudomonas cepacia was steadily immobilized on a new support prepared with metal-organic framework (MOF) and polyethyleneimine (PEI) through a PEI-boosted strategy (PS@MOF-5-PEI). Evaluated by the enantioselective transesterification reaction of racemic 1-(4-(trifluoromethyl) phenyl) ethanol (TFMP) with vinyl acetate, PS@MOF-5-PEI expressed more than 10 times of increase in specific activity (U/mg protein) compared with free lipase PS. PS@MOF-5-PEI had an enhanced enzyme-substrate affinity and catalytic efficiency than free lipase PS, as supported by a lower apparent Km value (7.3 vs 11.3 mM) and an increased Vmax/Km value (0.38 vs 0.05 min−1), respectively. Under the optimal conditions involving 45 °C, substrate ratio of 1:18, enzyme dosage of 20 mg and reaction time of 60 min, the ees of 99.8% and c of 50.1% for kinetic resolution of TFMP enantiomers were achieved with PS@MOF-5-PEI, which can be recycled for 10 times without significant loss in activity and with enantioselectivity well maintained.