title: Optimization of an industrial biocatalyst of glutaryl acylase: stabilization of the enzyme by multipoint covalent attachment onto new amino-epoxy Sepabeads.
abstract: Glutaryl-7-aminocephalosporanic acid acylase (GA), an industrially relevant enzyme, has been immobilized onto very different supports, including glyoxyl agarose, heterofunctional epoxy Sepabeads, glutaraldehyde and cyanogen bromide (CNBr) activated supports. Immobilization onto amino-epoxy Sepabeads rendered the most thermo stable preparation of GA, with a half-life time eight times higher than the soluble enzyme, keeping 80% of the enzyme activity. Several parameters that affect the enzyme-support interaction (pH and incubation time) were studied. It was found that after immobilization onto amino-epoxy Sepabeads, incubation at alkaline pH and low temperature exerted dramatic stabilizing effects, increasing the half-life time of the derivative 130 times with respect to the soluble enzyme, while keeping unaltered its intrinsic activity. The loading capacity of the amino-epoxy Sepabeads proved to be very good with a maximum load of 62 mg of protein per g of support with 85 IU/g at 25 degrees C and 200 IU/g at 37 degrees C which makes it a biocatalyst of possible industrial application.
authors.affiliation: Departamento de Biocatálisis, Instituto de Catálisis, CSIC, Campus Universidad Autonoma, Cantoblanco, 28049 Madrid, Spain.
authors.forename: Fernándo
authors.initials: F
authors.lastname: López-Gallego
authors.forename: Lorena
authors.initials: L
authors.lastname: Betancor
authors.forename: Aurelio
authors.initials: A
authors.lastname: Hidalgo
authors.forename: Cesar
authors.initials: C
authors.lastname: Mateo
authors.forename: Jose M
authors.initials: JM
authors.lastname: Guisán
authors.forename: Roberto
authors.initials: R
authors.lastname: Fernández-Lafuente
mesh_terms: D000327:Adsorption; D002384:Catalysis; D002617:Chemical Industry / Q000295:instrumentation*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D004789:Enzyme Activation; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry; D004853:Epoxy Resins / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008422:Materials Testing; D008863:Microspheres; D010399:Penicillin Amidase / Q000737:chemistry*; D011485:Protein Binding; D013696:Temperature
chemical_list: D020099:Coated Materials, Biocompatible; D004800:Enzymes, Immobilized; D004853:Epoxy Resins; D010399:Penicillin Amidase; C046586:glutarylamidocephalosporanic acid acylase