title: Characterization of cross-linked immobilized arylesterase from Gluconobacter oxydans 621H with activity toward cephalosporin C and 7-aminocephalosporanic acid.
abstract: Cross-linked enzyme aggregates (CLEAs) were prepared from several precipitant agents using glutaraldehyde as a cross-linking agent with and without BSA, finally choosing a 40% saturation of ammonium sulfate and 25 mM of glutaraldehyde. The CLEAs obtained under optimum conditions were biochemically characterized. The immobilized enzyme showed higher thermal activity and a broader range of pH and organic solvent tolerance than the free enzyme. Arylesterase from Gluconobacter oxydans showed activity toward cephalosporin C and 7-aminocephalosporanic acid. The CLEAs had a Kcat/KM of 0.9 M(-1) /S(-1) for 7-ACA (7-aminocephalosporanic acid) and 0.1 M(-1) /S(-1) for CPC (cephalosporin c), whereas free enzyme did not show a typical Michaelis-Menten kinetics.
authors.affiliation: Faculty of Biology, Department of Biochemistry and Molecular Biology-a, University of Murcia, Campus Espinardo, Murcia, E-30100, Spain.
authors.forename: Navarro-González
authors.initials: NG
authors.lastname: Inmaculada
authors.affiliation: Faculty of Biology, Department of Biochemistry and Molecular Biology-a, University of Murcia, Campus Espinardo, Murcia, E-30100, Spain.
authors.forename: García-Carmona
authors.initials: GC
authors.lastname: Francisco
mesh_terms: D002265:Carboxylic Ester Hydrolases / Q000737:chemistry*; D002511:Cephalosporins / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D004800:Enzymes, Immobilized / Q000737:chemistry*; D020600:Gluconobacter oxydans / Q000201:enzymology; D005976:Glutaral / Q000737:chemistry; D007700:Kinetics; D013696:Temperature
chemical_list: D002511:Cephalosporins; D003432:Cross-Linking Reagents; D004800:Enzymes, Immobilized; C025163:cephalosporin C; C030735:7-aminocephalosporanic acid; D002265:Carboxylic Ester Hydrolases; C019734:arylesterase; D005976:Glutaral
keywords: Gluconobacter oxydans; cross-linked enzyme aggregates; esterase; immobilization; β-lactam antibiotics