Improved performance of immobilized lipase by interfacial activation on Fe3O4@PVBC nanoparticles

Abstract

An effective strategy for enhancement of catalytic activity and stability of immobilized lipase by interfacial activation on Fe₃O₄@PVBC (Fe₃O₄@polyvinylbenzyl chloride) nanoparticles was developed, which involved the fabrication of core–shelled Fe₃O₄@PVBC nanoparticles via an emulsion polymerization process and the subsequent immobilization of lipase in phosphate buffer. Due to the magnetic nature of Fe₃O₄ cores and the presence of chloromethyl-functionalized polymer shells, the Fe₃O₄@PVBC nanoparticles were employed as valid magnetic carriers for lipase immobilization. Bradford assays indicated that the loading amount of lipase on the Fe₃O₄@PVBC nanoparticles was calculated to be 162.5 mg protein per g particles. The catalytic activity of the immobilized lipase retained about 99.6 ± 3.3% of the free enzyme activity, which was attributed to interfacial activation of lipase by Fe₃O₄@PVBC nanoparticles. Thermal and urea tolerance tests revealed that the immobilized lipase exhibited much better stabilities. Additionally, the immobilized lipase retained more than 69.8% of its initial activities after 10 times of reuse. It is believed that the results of the present investigation may provide a versatile approach for designing and fabricating biocatalysts with high activation and stability.