title: Effect of poly(vinyl acetate-acrylamide) microspheres properties and steric hindrance on the immobilization of Candida rugosa lipase.
abstract: Poly(vinyl acetate-acrylamide) microspheres were synthesized in the absence or presence of isooctane via suspension polymerization and utilized as carriers to immobilize Candida rugosa lipase. When the hydrophobic/hydrophilic surface characteristics of the microspheres were modified by changing the ratio of vinyl acetate (hydrophobic monomer) to acrylamide (hydrophilic monomer) from 50:50 to 86:24, the immobilization ratio changed from 45% to 92% and the activity of the immobilized lipase increased from 202.5 to 598.0 U/g microsphere. Excessive lipase loading caused intermolecular steric hindrance, which resulted in a decline in lipase activity. The maximum specific activity of the immobilized lipase (4.65 U/mg lipase) was higher than that of free lipase (3.00 U/mg lipase), indicating a high activity recovery during immobilization.
authors.affiliation: College of Pharmacy, Hebei University, Baoding 071002, China. zhangdonghao1@gmail.com
authors.forename: Dong-Hao
authors.initials: DH
authors.lastname: Zhang
authors.forename: Li-Xia
authors.initials: LX
authors.lastname: Yuwen
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.forename: Ya-Qiong
authors.initials: YQ
authors.lastname: Li
mesh_terms: D020106:Acrylamide / Q000737:chemistry*; D002175:Candida / Q000201:enzymology*; D004800:Enzymes, Immobilized / Q000378:metabolism*; D008049:Lipase / Q000378:metabolism*; D008863:Microspheres; D011145:Polyvinyls / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D004800:Enzymes, Immobilized; D011145:Polyvinyls; D020106:Acrylamide; C013215:polyvinyl acetate; D008049:Lipase