title: The properties of covalently immobilized trypsin on soap-free P(MMA-EA-AA) latex particles.
abstract: The covalent immobilization of trypsin onto poly[(methyl methacrylate)-co-(ethyl acrylate)-co-(acrylic acid)] latex particles, produced by a soap-free emulsion polymerization technique, was carried out using the carbodiimide method. The catalytic properties and kinetic parameters, as well as the stability of the immobilized enzyme were compared to those of the free enzyme. Results showed that the optimum temperature and pH for the immobilized trypsin in the hydrolysis of casein were 55 degrees C and 8.5, both of which were higher than that of the free form. It was found that K(m) (Michaelis constant) was 45.7 mg . ml(-1) and V(max) (maximal reaction rate) was 793.0 microg . min(-1) for immobilized trypsin, compared to a K(m) of 30.0 mg . ml(-1) and a V(max) of 5 467.5 microg . min(-1) for free trypsin. The immobilized trypsin exhibited much better thermal and chemical stabilities than its free counterpart and maintained over 63% of its initial activity after reusing ten times.
authors.affiliation: Department of Chemical Engineering, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: Kai
authors.initials: K
authors.lastname: Kang
authors.forename: Chengyou
authors.initials: C
authors.lastname: Kan
authors.forename: Anthony
authors.initials: A
authors.lastname: Yeung
authors.forename: Deshan
authors.initials: D
authors.lastname: Liu
mesh_terms: D004800:Enzymes, Immobilized / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008863:Microspheres; D011109:Polymethacrylic Acids / Q000737:chemistry*; D012915:Soaps / Q000737:chemistry; D013379:Substrate Specificity; D013696:Temperature; D014357:Trypsin / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; D011109:Polymethacrylic Acids; D012915:Soaps; C505109:poly((methyl methacrylate)-co-(ethyl acrylate)-co-(acrylic acid)); D014357:Trypsin