title: Solution structure of agelenin, an insecticidal peptide isolated from the spider Agelena opulenta, and its structural similarities to insect-specific calcium channel inhibitors.
abstract: Agelenin, isolated from the Agelenidae spider Agelena opulenta, is a peptide composed of 35 amino acids. We determined the three-dimensional structure of agelenin using two-dimensional NMR spectroscopy. The structure is composed of a short antiparallel beta-sheet and four beta-turns, which are stabilized by three disulfide bonds. Agelenin has characteristic residues, Phe9, Ser28 and Arg33, which are arranged similarly to the pharmacophore of the insect channel inhibitor, omega-atracotoxin-Hv1a. These observations suggest that agelenin and omega-atracotoxin-Hv1a bind to insect calcium channels in a similar manner. We also suggest that another mode of action may operate in the channel inhibition by omega-agatoxin-IVA and omega-atracotoxin-Hv2a.
authors.affiliation: Suntory Institute for Bioorganic Research, 1-1-1 Wakayamadai, Shimamoto-Cho, Mishima-Gun, Osaka 618-8503, Japan.
authors.forename: Nahoko
authors.initials: N
authors.lastname: Yamaji
authors.forename: Kenji
authors.initials: K
authors.lastname: Sugase
authors.forename: Terumi
authors.initials: T
authors.lastname: Nakajima
authors.forename: Takafumi
authors.initials: T
authors.lastname: Miki
authors.forename: Minoru
authors.initials: M
authors.lastname: Wakamori
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Mori
authors.forename: Takashi
authors.initials: T
authors.lastname: Iwashita
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001120:Arginine / Q000737:chemistry; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002460:Cell Line; D004220:Disulfides / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D006135:Gryllidae / Q000187:drug effects; D006801:Humans; D007306:Insecticides / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D018408:Patch-Clamp Techniques; D010455:Peptides / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D010649:Phenylalanine / Q000737:chemistry; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017386:Sequence Homology, Amino Acid; D012694:Serine / Q000737:chemistry; D013111:Spider Venoms / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D013112:Spiders / Q000737:chemistry*
chemical_list: D002121:Calcium Channel Blockers; D004220:Disulfides; D007306:Insecticides; D010455:Peptides; D013111:Spider Venoms; C077703:agelenin; D012694:Serine; D010649:Phenylalanine; D001120:Arginine