title: Antimicrobial activity and conformation of tachyplesin I and its analogs.
abstract: We investigated the structure-antimicrobial activity relationship of tachyplesin I (T-I). Even when Lys1 and Trp2 were both deleted from the N-terminal end of T-I, the antimicrobial activity against gram-negative bacteria was not decreased. But as Lys1 and Trp2 were deleted one by one, the antimicrobial activity against gram-positive bacteria and antiviral activity were gradually decreased. Deletion of two disulfide bridges caused a significant decrease in all activities. The circular dichroism (CD) spectra revealed that the analogs containing the two disulfide bridges took a beta-sheet structure and that the analogs without the disulfide bridges took a random coil conformation. These results suggest that the beta-sheet structure maintained by two disulfide bridges plays an important role in the antimicrobial activity of T-I.
authors.affiliation: Faculty of Pharmaceutical Sciences, Kyoto University, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Tamamura
authors.forename: R
authors.initials: R
authors.lastname: Ikoma
authors.forename: M
authors.initials: M
authors.lastname: Niwa
authors.forename: S
authors.initials: S
authors.lastname: Funakoshi
authors.forename: T
authors.initials: T
authors.lastname: Murakami
authors.forename: N
authors.initials: N
authors.lastname: Fujii
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides; D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic; D011487:Protein Conformation; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D000998:Antiviral Agents; D004268:DNA-Binding Proteins; D010456:Peptides, Cyclic; C057636:tachyplesin peptide, Tachypleus tridentatus