title: Immobilization of Aspergillus terreus lipase in self-assembled hollow nanospheres for enantioselective hydrolysis of ketoprofen vinyl ester.
abstract: The aim of this study was to improve the ability of Aspergillus terreus lipase to separate the racemic ketoprofen vinyl ester into individual enantiomers using hollow self-assembly alginate-graft-poly(ethylene glycol)/α-cyclodextrins (Alg-g-PEG/α-CD) spheres as enzyme immobilization carriers. The morphology and size of the Alg-g-PEG/α-CD particles were investigated by transmission electron microscopy (TEM) and were found to be nanoscale. To facilitate recycling, calcium alginate (CA) beads were developed to encapsulate Alg-g-PEG/α-CD particles, thereby producing Alg-g-PEG/α-CD/CA composite beads. The influence of buffer pH and enzyme concentration during immobilization was studied along with the biocatalyst's kinetic parameters. When the immobilized enzyme was under optimal conditions in the resolution reaction, maximal conversion (approximately 45.9%) and enantioselectivity (approximately 128.8) were obtained. The immobilized A. terreus lipase maintained excellent performance even after 20 reuses and retained nearly 100% of its original activity after 24 weeks of storage at 4°C.
authors.affiliation: Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, PR China.
authors.forename: Chengli
authors.initials: C
authors.lastname: Hu
authors.affiliation: Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, PR China. Electronic address: wnchem@scu.edu.cn.
authors.forename: Na
authors.initials: N
authors.lastname: Wang
authors.affiliation: Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, PR China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610064, PR China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Bio-Resources and Eco-Environment, College of Life Science, Sichuan University, Chengdu 610064, PR China.
authors.forename: Yanfa
authors.initials: Y
authors.lastname: Meng
authors.affiliation: Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, PR China. Electronic address: xqyu@scu.edu.cn.
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Yu
mesh_terms: D001230:Aspergillus / Q000201:enzymology*; D004800:Enzymes, Immobilized / Q000378:metabolism*; D004952:Esters / Q000737:chemistry*; D006868:Hydrolysis; D007660:Ketoprofen / Q000737:chemistry*; D008049:Lipase / Q000378:metabolism*; D054118:Nanospheres; D013237:Stereoisomerism
chemical_list: D004800:Enzymes, Immobilized; D004952:Esters; D007660:Ketoprofen; D008049:Lipase
keywords: Hollow nanospheres; Immobilization lipase; Ketoprofen vinyl ester; Kinetic resolution