title: Isolation of peptide ligands that inhibit glutamate racemase activity from a random phage display library.
abstract: Several new antibacterial agents are currently being developed in response to the emergence of bacterial resistance to existing antibiotic substances. The new agents include compounds that interfere with bacterial membrane function. The peptidoglycan component of the bacterial cell wall is synthesized by glutamate racemase, and this enzyme is responsible for the biosynthesis of d-glutamate, which is an essential component of cell wall peptidoglycan. In this study, we screened a phage display library expressing random dodecapeptides on the surface of bacteriophage against an Escherichia coli glutamate racemase, and isolated specific peptide sequences that bind to the enzyme. Twenty-seven positive phage clones were analyzed, and seven different peptide sequences were obtained. Among them, the peptide sequence His-Pro-Trp-His-Lys-Lys-His-Pro-Asp-Arg-Lys-Thr was found most frequently, suggesting that this peptide might have the highest affinity to glutamate racemase. The positive phage clones and HPWHKKHPDRKT synthetic peptide were able to inhibit glutamate racemase activity in vitro, implying that our peptide inhibitors may be utilized for the molecular design of new potential antibacterial agents targeting cell wall synthesis.
authors.affiliation: Division of Food Science and Biotechnology, College of Agriculture and Life Sciences, Kangwon National University, Chunchon 200-701, South Korea.
authors.forename: W C
authors.initials: WC
authors.lastname: Kim
authors.forename: H I
authors.initials: HI
authors.lastname: Rhee
authors.forename: B K
authors.initials: BK
authors.lastname: Park
authors.forename: K H
authors.initials: KH
authors.lastname: Suk
authors.forename: S H
authors.initials: SH
authors.lastname: Cha
mesh_terms: D000591:Amino Acid Isomerases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects / Q000378:metabolism; D001483:Base Sequence; D002473:Cell Wall / Q000187:drug effects / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D015195:Drug Design; D004353:Drug Evaluation, Preclinical; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D008024:Ligands; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D019151:Peptide Library; D011993:Recombinant Fusion Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D017931:DNA Primers; D004791:Enzyme Inhibitors; D008024:Ligands; D009842:Oligopeptides; D019151:Peptide Library; D011993:Recombinant Fusion Proteins; D000591:Amino Acid Isomerases; C062292:glutamate racemase