title: Validation of inhibitors of an ABC transporter required to transport lipopolysaccharide to the cell surface in Escherichia coli.
abstract: The presence of lipopolysaccharide (LPS) in the outer leaflet of the outer membrane (OM) of Gram-negative bacteria creates a permeability barrier that prevents the entry of most currently available antibiotics. The seven lipopolysaccharide transport (Lpt) proteins involved in transporting and assembling this glycolipid are essential for growth and division in Escherichia coli; therefore, inhibiting their functions leads to cell death. LptB, the ATPase that provides energy for LPS transport and assembly, forms a complex with three other inner membrane (IM) components, LptC, F, and G. We demonstrate that inhibitors of pure LptB can also inhibit the full IM complex, LptBFGC, purified in detergent. We also compare inhibition of LptB and the LptBFGC complex with the antibiotic activity of these compounds. Our long-term goal is to develop tools to study inhibitors of LPS biogenesis that could serve as potentiators by disrupting the OM permeability barrier, facilitating entry of clinically used antibiotics not normally used to treat Gram-negative infections, or that can serve as antibiotics themselves.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Str., Cambridge, MA 02138, United States. dsherman@fas.harvard.edu
authors.forename: David J
authors.initials: DJ
authors.lastname: Sherman
authors.forename: Suguru
authors.initials: S
authors.lastname: Okuda
authors.forename: William A
authors.initials: WA
authors.lastname: Denny
authors.forename: Daniel
authors.initials: D
authors.lastname: Kahne
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D001692:Biological Transport; D002473:Cell Wall / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D008070:Lipopolysaccharides / Q000378:metabolism*; D008826:Microbial Sensitivity Tests; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D054852:Small Molecule Libraries / Q000737:chemistry / Q000494:pharmacology
chemical_list: D018528:ATP-Binding Cassette Transporters; D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D008070:Lipopolysaccharides; D011993:Recombinant Fusion Proteins; D054852:Small Molecule Libraries
keywords: ABC transporter; Antibiotics; Gram-negative; Lipopolysaccharide