title: Galactose- and maltose-stimulated lipoamide dehydrogenase activities related to the binding-protein-dependent transport of galactose and maltose in toluenized cells of Escherichia coli.
abstract: The binding protein-dependent transport of galactose and maltose occurs at a reduced but significant rate in Escherichia coli cells which have undergone a mild toluenization. Dihydrolipoate and 3-acetyl-NAD produce a severalfold stimulation of these transports in the toluenized cells. In parallel to the stimulation of galactose and maltose transport by dihydrolipoate and 3-acetyl-NAD, there is a stimulation by galactose and maltose of lipoamide dehydrogenase activities which seem to be related to the binding-protein-dependent transport of these sugars. The lipoamide dehydrogenase component of the pyruvate and 2-oxoglutarate dehydrogenase complexes (the lpd gene product) is not involved in this stimulation. These results are discussed in relation to our recent studies showing a possible involvement of lipoic acid and of the 2-oxoacid dehydrogenases in the binding-protein-dependent transports.
mesh_terms: D018528:ATP-Binding Cassette Transporters; D001692:Biological Transport; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins / Q000378:metabolism*; D008058:Dihydrolipoamide Dehydrogenase / Q000378:metabolism*; D004492:Edetic Acid; D004789:Enzyme Activation / Q000187:drug effects; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D005690:Galactose / Q000378:metabolism / Q000494:pharmacology*; D005798:Genes, Bacterial; D008320:Maltose / Q000378:metabolism / Q000494:pharmacology*; D058619:Maltose-Binding Proteins; D009004:Monosaccharide Transport Proteins; D009154:Mutation; D009243:NAD / Q000031:analogs & derivatives / Q000494:pharmacology; D009876:Operon; D033902:Periplasmic Binding Proteins; D008063:Thioctic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D014050:Toluene
chemical_list: D018528:ATP-Binding Cassette Transporters; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D058619:Maltose-Binding Proteins; D009004:Monosaccharide Transport Proteins; D033902:Periplasmic Binding Proteins; C023550:galactose-binding protein; C461599:maltose transport system, E coli; D009243:NAD; D014050:Toluene; D008320:Maltose; D008063:Thioctic Acid; C015144:dihydrolipoic acid; C005941:3-acetylpyridine adenine dinucleotide; D004492:Edetic Acid; D008058:Dihydrolipoamide Dehydrogenase; D005690:Galactose