title: Lipase immobilization on epoxy-activated poly(vinyl acetate-acrylamide) microspheres.
abstract: Poly(vinyl acetate-acrylamide) microspheres with an average diameter of 2-4μm were successfully prepared and characterized via SEM and FTIR. Then the microspheres were modified with epoxy groups through reacting with epichlorohydrin and used as carriers to covalently immobilize Candida rugosa lipase. The results revealed that agitation played an important role on epoxy activation and the immobilization ratio increased with the increase of the epoxy density. On the other hand, the specific activity of the immobilized lipase as well as the activity recovery declined gradually with the increase in the immobilization ratio from 72% to 93%, which were attributed to the steric hindrance effects caused by enzyme overloading. When epoxy density was 76μmol/g microsphere, the activity recovery reached the maximum at 47.5%, and the activity of the immobilized lipase was 261.3U/g microsphere. Moreover, the thermal stability of the immobilized lipase was much better than that of the free one, which indicated potential applications of the immobilized lipase.
authors: College of Pharmaceutical Science, Hebei University, Baoding 071002, China; Key Laboratory of Pharmaceutical Quality Control of Hebei Province, College of Pharmaceutical Science, Hebei University, Baoding 071002, China. Electronic address: donghaozhang1@163.com.
authors: Dong-Hao
authors: DH
authors: Zhang
authors: College of Pharmaceutical Science, Hebei University, Baoding 071002, China.
authors: Li-Juan
authors: LJ
authors: Peng
authors: College of Pharmaceutical Science, Hebei University, Baoding 071002, China.
authors: Yun
authors: Y
authors: Wang
authors: College of Pharmaceutical Science, Hebei University, Baoding 071002, China.
authors: Ya-Qiong
authors: YQ
authors: Li
mesh_terms: D020106:Acrylamide / Q000737:chemistry*; D002175:Candida / Q000201:enzymology*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D004853:Epoxy Resins / Q000737:chemistry*; D005227:Fatty Acids / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008049:Lipase / Q000737:chemistry / Q000378:metabolism*; D008863:Microspheres; D011145:Polyvinyls / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
chemical_list: D004800:Enzymes, Immobilized; D004853:Epoxy Resins; D005227:Fatty Acids; D011145:Polyvinyls; D020106:Acrylamide; C013215:polyvinyl acetate; D008049:Lipase
keywords: Agitation; Epoxy activation; Epoxy density; Lipase immobilization; Microsphere