title: A new, mild cross-linking methodology to prepare cross-linked enzyme aggregates.
abstract: Cross-linked enzyme aggregates (CLEAs) were prepared from several enzymes (penicillin G acylase, hydroxynitrile lyase, alcohol dehydrogenase, and two different nitrilases) by precipitation and subsequent cross-linking using dextran polyaldehyde. In most cases, higher immobilization yields were obtained using the latter cross-linker as compared with the commonly used glutaraldehyde. Active site titration of penicillin acylase CLEAs showed that the higher activity originated from a significantly lower loss in active sites using dextran polyaldehyde as a cross-linking agent. It is proposed that macromolecular cross-linkers are too large to penetrate the protein active site and react with catalytically essential amino acid residues.
authors.affiliation: Laboratory of Biocatalysis and Organic Chemistry, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands. boc-secretariat@tnw.tudelft.nl
authors.forename: Cesar
authors.initials: C
authors.lastname: Mateo
authors.forename: José M
authors.initials: JM
authors.lastname: Palomo
authors.forename: Luuk M
authors.initials: LM
authors.lastname: van Langen
authors.forename: Fred
authors.initials: F
authors.lastname: van Rantwijk
authors.forename: Roger A
authors.initials: RA
authors.lastname: Sheldon
mesh_terms: D001665:Binding Sites; D002384:Catalysis; D003432:Cross-Linking Reagents / Q000378:metabolism*; D003911:Dextrans / Q000378:metabolism; D004800:Enzymes, Immobilized / Q000378:metabolism; D005976:Glutaral / Q000378:metabolism; D008970:Molecular Weight; D010399:Penicillin Amidase / Q000378:metabolism
chemical_list: D003432:Cross-Linking Reagents; D003911:Dextrans; D004800:Enzymes, Immobilized; C026948:dextran dialdehyde; D010399:Penicillin Amidase; D005976:Glutaral