title: Physical and kinetic effects on induction of various linker regions in beta-galactosidase/galactose dehydrogenase fusion enzymes.
abstract: To examine the role of the connecting region in the artificial bifunctional enzyme beta-galactosidase/galactose dehydrogenase, linkers of different length were inserted between the catalytic units. The specific activity of the galactose dehydrogenase part of the complex was increased when longer linkers (9 and 13 amino acids) were used as connectors. These bifunctional enzymes were predominantly found to comprise hexamers, however, complexes of higher molecular weight were also formed. The sequential reaction was carried out more efficiently when hybrid enzymes with the longer linkers were used as demonstrated both in vitro by using purified protein preparations as well as in vivo by determining the growth rates of recombinant E. coli cells on a minimal medium containing lactose.
authors.affiliation: Department of Pure and Applied Biochemistry, Lund, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Carlsson
authors.forename: S
authors.initials: S
authors.lastname: Ljung
authors.forename: L
authors.initials: L
authors.lastname: Bülow
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development; D005690:Galactose / Q000378:metabolism; D005691:Galactose Dehydrogenases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007785:Lactose / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000378:metabolism; D013696:Temperature; D001616:beta-Galactosidase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D009097:Multienzyme Complexes; D010455:Peptides; D011993:Recombinant Fusion Proteins; D009243:NAD; D005691:Galactose Dehydrogenases; C047959:galactose dehydrogenase; D001616:beta-Galactosidase; D007785:Lactose; D005690:Galactose