title: Low 13C-background for NMR-based studies of ligand binding using 13C-depleted glucose as carbon source for microbial growth: 13C-labeled glucose and 13C-forskolin binding to the galactose-H+ symport protein GalP in Escherichia coli.
abstract: Obtrusive 13C-backgrounds can be a problem in 13C NMR-based studies of ligand binding to bacterial membrane transport proteins in their natural state in inner membranes. This is largely solved for the bacterial galactose-H+ symport protein GalP by growing the producing organism Escherichia coli on 13C-depleted glucose (13C </= 0.07%) as the main carbon source. 13C solid-state NMR-based binding studies for the inhibitor forskolin 1 and the transported substrate glucose 2, both singly labeled with 13C, are reported and discussed. For 1, tight binding is observed, while for 2, significant exchange takes place during the time scale of the NMR experiment.
authors.affiliation: Astbury Center for Structural Molecular Biology and Institute of Materials Research, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: Simon G
authors.initials: SG
authors.lastname: Patching
authors.forename: Richard B
authors.initials: RB
authors.lastname: Herbert
authors.forename: John
authors.initials: J
authors.lastname: O'Reilly
authors.forename: Adrian R
authors.initials: AR
authors.lastname: Brough
authors.forename: Peter J F
authors.initials: PJ
authors.lastname: Henderson
mesh_terms: D002135:Calcium-Binding Proteins; D002247:Carbon Isotopes; D005576:Colforsin / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism*; D005947:Glucose / Q000737:chemistry / Q000378:metabolism*; D007553:Isotope Labeling; D008024:Ligands; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D033902:Periplasmic Binding Proteins / Q000378:metabolism*; D011485:Protein Binding
chemical_list: D002135:Calcium-Binding Proteins; D002247:Carbon Isotopes; D008024:Ligands; D009004:Monosaccharide Transport Proteins; D033902:Periplasmic Binding Proteins; C023550:galactose-binding protein; D005576:Colforsin; D005947:Glucose