title: Secondary structure determination for alpha-neurotoxin from Dendroaspis polylepis polylepis based on sequence-specific 1H-nuclear-magnetic-resonance assignments.
abstract: Sequence-specific assignments are presented for the polypeptide backbone protons and a majority of the amino-acid-side-chain protons of alpha-neurotoxin from Dendroaspis polylepis polylepis, and individual amide proton-exchange rates with the solvent are reported. The secondary structure and the hydrogen-bonding patterns in the regular secondary structure elements are deduced from nuclear Overhauser effects and the sequence locations of the slowly exchanging amide protons. The molecule includes a three-stranded antiparallel beta-sheet, and there are indications that two additional short chain segments are arranged in an antiparallel beta-sheet. These structural elements are similar, but not identical, to either the secondary structure reported for erabutoxin b in single crystals, or the solution structure of cytotoxin CTXIIb from Naja mossambica mossambica.
authors.affiliation: Institut für Molekularbiologie und Biophysik, Eidgenössische Technische Hochschule-Hönggerberg, Zürich, Switzerland.
authors.forename: A M
authors.initials: AM
authors.lastname: Labhardt
authors.forename: E H
authors.initials: EH
authors.lastname: Hunziker-Kwik
authors.forename: K
authors.initials: K
authors.lastname: Wüthrich
mesh_terms: D000577:Amides; D004546:Elapid Venoms / Q000032:analysis*; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D009498:Neurotoxins; D011487:Protein Conformation; D011522:Protons; D012996:Solutions
chemical_list: D000577:Amides; D004546:Elapid Venoms; D009498:Neurotoxins; D011522:Protons; D012996:Solutions