title: Interaction between tachyplesin I, an antimicrobial peptide derived from horseshoe crab, and lipopolysaccharide.
abstract: Lipopolysaccharide (LPS) is a major constituent of the outer membrane of Gram-negative bacteria and is the very first site of interactions with antimicrobial peptides (AMPs). In order to gain better insight into the interaction between LPS and AMPs, we determined the structure of tachyplesin I (TP I), an antimicrobial peptide derived from horseshoe crab, in its bound state with LPS and proposed the complex structure of TP I and LPS using a docking program. CD and NMR measurements revealed that binding to LPS slightly extends the two β-strands of TP I and stabilizes the whole structure of TP I. The fluorescence wavelength of an intrinsic tryptophan of TP I and fluorescence quenching in the presence or absence of LPS indicated that a tryptophan residue is incorporated into the hydrophobic environment of LPS. Finally, we succeeded in proposing a structural model for the complex of TP I and LPS by using a docking program. The calculated model structure suggested that the cationic residues of TP I interact with phosphate groups and saccharides of LPS, whereas hydrophobic residues interact with the acyl chains of LPS.
authors.affiliation: Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan. Electronic address: kushibiki@mail.sci.hokudai.ac.jp.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kushibiki
authors.affiliation: Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan. Electronic address: mkamiya@sci.hokudai.ac.jp.
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Kamiya
authors.affiliation: Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan. Electronic address: aizawa@mail.sci.hokudai.ac.jp.
authors.forename: Tomoyasu
authors.initials: T
authors.lastname: Aizawa
authors.affiliation: Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan. Electronic address: kumaki@sci.hokudai.ac.jp.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kumaki
authors.affiliation: Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan. Electronic address: kikukawa@sci.hokudai.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kikukawa
authors.affiliation: Faculty of Pharmaceutical Sciences, University of Toyama, 2630, Sugitani, Toyama 930-0194, Japan. Electronic address: mineyuki@pha.u-toyama.ac.jp.
authors.forename: Mineyuki
authors.initials: M
authors.lastname: Mizuguchi
authors.affiliation: Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan. Electronic address: demura@sci.hokudai.ac.jp.
authors.forename: Makoto
authors.initials: M
authors.lastname: Demura
authors.affiliation: Department of Biology, Kyusyu University, Fukuoka, Fukuoka 812-8581, Japan. Electronic address: skawascb@kyudai.jp.
authors.forename: Shun-ichiro
authors.initials: S
authors.lastname: Kawabata
authors.affiliation: Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan. Electronic address: kawano@sci.hokudai.ac.jp.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kawano
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry*; D002942:Circular Dichroism; D004268:DNA-Binding Proteins / Q000737:chemistry*; D006737:Horseshoe Crabs; D008070:Lipopolysaccharides / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D010456:Peptides, Cyclic / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D004268:DNA-Binding Proteins; D008070:Lipopolysaccharides; D010456:Peptides, Cyclic; C057636:tachyplesin peptide, Tachypleus tridentatus
keywords: Antimicrobial peptide; Docking calculation; Lipopolysaccharide; NMR; Tachyplesin I