Enzyme immobilization on a novel NH2-MOF-5@PEI composite support for efficient kinetic resolution of MOPE enantiomers

Abstract

The immobilization of enzyme on solid supports as the heterogeneous catalyst is an efficient strategy to enhance the catalytic performance and reusability. MOFs supports show huge potential for enzyme immobilization, however, suffer from poor stability thus reducing the effective loading of enzyme and resulting in low catalytic performance. In this work, NH2-MOF-5 was synthesized and linked with the cross-linked PEI by chemical bond to form a novel composite support, the lipase PS was then immobilized onto the composite support through physical adsorption to synthesized PS@NH2-MOF-5@PEI in hexane. Benefitting from the stable nano-flower structure and strong adsorption for lipase PS of the NH2-MOF-5@PEI, the synthesized PS@NH2-MOF-5@PEI showed huge specific surface area (only decreased 5.90 % after immobilization) and enhanced α-helix and β-turn (increased 29.80 % and 52.88 %, respectively), thus exhibiting excellent catalytic activity which was about 2 times higher than that of free lipase PS, as well as outstanding recyclability after 8 cycles. We believe the strategy of immobilization of enzymes on a novel NH2-MOF-5@PEI support will exhibit huge potential of biocatalyst for further application.