title: A MurF inhibitor that disrupts cell wall biosynthesis in Escherichia coli.
abstract: MurF is an essential enzyme of bacterial cell wall biosynthesis. Few MurF inhibitors have been reported, and none have displayed measurable antibacterial activity. Through the use of a MurF binding assay, a series of 8-hydroxyquinolines that bound to the Escherichia coli enzyme and inhibited its activity was identified. To derive additional chemotypes lacking 8-hydroxyquinoline, a known chelating moiety, a pharmacophore model was constructed from the series and used to select compounds for testing in the MurF binding and enzymatic inhibition assays. Whereas the original diverse library yielded 0.01% positive compounds in the binding assay, of which 6% inhibited MurF enzymatic activity, the pharmacophore-selected set yielded 14% positive compounds, of which 37% inhibited the enzyme, suggesting that the model enriched for compounds with affinity to MurF. A 4-phenylpiperidine (4-PP) derivative identified by this process displayed antibacterial activity (MIC of 8 microg/ml against permeable E. coli) including cell lysis and a 5-log(10)-unit decrease in CFU. Importantly, treatment of E. coli with 4-PP resulted in a 15-fold increase in the amount of the MurF UDP-MurNAc-tripeptide substrate, and a 50% reduction in the amount of the MurF UDP-MurNAc-pentapeptide product, consistent with inhibition of the MurF enzyme within bacterial cells. Thus, 4-PP is the first reported inhibitor of the MurF enzyme that may contribute to antibacterial activity by interfering with cell wall biosynthesis.
authors.affiliation: Johnson & Johnson Pharmaceutical Research & Development, L.L.C., 1000 Route 202, Raritan, NJ 08869, USA. ebaum@prdus.jnj.com
authors.forename: Ellen Z
authors.initials: EZ
authors.lastname: Baum
authors.forename: Steven M
authors.initials: SM
authors.lastname: Crespo-Carbone
authors.forename: Alexandra
authors.initials: A
authors.lastname: Klinger
authors.forename: Barbara D
authors.initials: BD
authors.lastname: Foleno
authors.forename: Ignatius
authors.initials: I
authors.lastname: Turchi
authors.forename: Mark
authors.initials: M
authors.lastname: Macielag
authors.forename: Karen
authors.initials: K
authors.lastname: Bush
mesh_terms: D002473:Cell Wall / Q000378:metabolism*; D003523:Cycloserine / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D008958:Models, Molecular; D015394:Molecular Structure; D015125:Oxyquinoline / Q000737:chemistry / Q000494:pharmacology; D010453:Peptide Synthases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013997:Time Factors
chemical_list: D004791:Enzyme Inhibitors; D029968:Escherichia coli Proteins; D015125:Oxyquinoline; D003523:Cycloserine; D010453:Peptide Synthases; C060628:UDP-N-acetylmuramoylalanyl-D-glutamyllysine-D-alanyl-D-alanine ligase