title: Dual targeting antibacterial peptide inhibitor of early lipid A biosynthesis.
abstract: UDP-3-O-(R-3-hydroxyacyl)GlcN N-acyltransferase (LpxD) has been shown to be essential to survival of lipid A producing Gram-negative bacteria. In this study, LpxD-binding peptides 12 amino acids in length were identified from a phage-bound random peptide library screen. Three peptides displayed antibacterial activity when expressed intracellularly, one of which (RJPXD33) represented 15% of the total hits. RJPXD33 binds to E. coli LpxD with a K(d) of 6 μM and is competitive with R-3-hydroxymyristoyl-ACP binding. RJPXD33 can be C-terminally fused in vivo with thioredoxin or N-terminally modified in vitro with β-alanyl-fluorescein and maintain LpxD binding. The latter was used to develop an LpxD fluorescent binding assay used to evaluate unlabeled ligands and is amenable to small molecule library screening. Furthermore, RJPXD33 also binds to and inhibits E. coli UDP-N-acetylglucosamine acyltransferase (LpxA) with a K(d) of 20 μM, unearthing the possibility for the development of small molecule, dual-binding LpxA/LpxD inhibitors as novel antimicrobials.
authors.affiliation: Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, 48109, United States.
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Jenkins
authors.forename: Garry D
authors.initials: GD
authors.lastname: Dotson
mesh_terms: D000217:Acyltransferases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000378:metabolism; D001665:Binding Sites / Q000502:physiology; D016503:Drug Delivery Systems / Q000379:methods*; D008050:Lipid A / Q000037:antagonists & inhibitors* / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D008050:Lipid A; D000217:Acyltransferases; C050304:acyl-(acyl-carrier-protein)-UDP-N-acetylglucosamine acyltransferase