title: Binding of peptides in solution by the Escherichia coli chaperone PapD as revealed using an inhibition ELISA and NMR spectroscopy.
abstract: PapD is the prototype member of a family of periplasmic chaperones which are required for assembly of virulence associated pili in pathogenic, gram-negative bacteria. In the present investigation, an ELISA has been developed for evaluation of compounds as inhibitors of PapD. Synthetic peptides, including an octamer, derived from the C-terminus of the pilus adhesin PapG were able to inhibit PapD in the ELISA. Evaluation of a panel of octapeptides in the ELISA, in combination with NMR studies, showed that the peptides were bound as extended beta-strands by PapD in aqueous solution. The PapD-peptide complex was stabilized by backbone to backbone hydrogen bonds and interactions involving three hydrophobic peptide side chains. This structural information, together with previous crystal structure data, provides a starting point in efforts to design and synthesize compounds which bind to chaperones and interfere with pilus assembly in pathogenic bacteria.
authors.affiliation: Center for Chemistry and Chemical Engineering, Lund University, Sweden.
authors.forename: K F
authors.initials: KF
authors.lastname: Karlsson
authors.forename: B
authors.initials: B
authors.lastname: Walse
authors.forename: T
authors.initials: T
authors.lastname: Drakenberg
authors.forename: S
authors.initials: S
authors.lastname: Roy
authors.forename: K E
authors.initials: KE
authors.lastname: Bergquist
authors.forename: J S
authors.initials: JS
authors.lastname: Pinkner
authors.forename: S J
authors.initials: SJ
authors.lastname: Hultgren
authors.forename: J
authors.initials: J
authors.lastname: Kihlberg
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins; D007202:Indicators and Reagents; D007700:Kinetics; D018832:Molecular Chaperones / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D010446:Peptide Fragments / Q000737:chemistry*; D033903:Periplasmic Proteins; D017433:Protein Structure, Secondary; D012996:Solutions; D013329:Structure-Activity Relationship
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D007202:Indicators and Reagents; D018832:Molecular Chaperones; D009842:Oligopeptides; C084330:PapD protein, E coli; D010446:Peptide Fragments; D033903:Periplasmic Proteins; D012996:Solutions