title: Solution structure of alpha-conotoxin ImI determined by two-dimensional NMR spectroscopy.
abstract: The three-dimensional structure of alpha-conotoxin ImI, a potent antagonist targeting the neuronal alpha7 subtype of nicotinic acetylcholine receptor (nAChR), has been investigated by NMR spectroscopy. On the basis of 181 experimental constraints, a total of 25 converged structures were obtained. The average pairwise atomic root mean square difference is 0.40+/-0.11 A for the backbone atoms. The resulting structure indicates the presence of two successive type I beta-turns and a 310 helix for residues Cys2-Cys8 and Ala9-Arg11, respectively, and shows a significant structural similarity to that of alpha-conotoxin PnIA, which is also selective for the neuronal nAChR.
authors.affiliation: School of Pharmaceutical Sciences, Kitasato University, Shirokane, Minato-ku, Tokyo 108-8641, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Gouda
authors.forename: S
authors.initials: S
authors.lastname: Hirono
mesh_terms: D020916:Conotoxins; D015195:Drug Design; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D015394:Molecular Structure; D008978:Mollusk Venoms / Q000737:chemistry*; D009842:Oligopeptides / Q000737:chemistry* / Q000235:genetics; D011978:Receptors, Nicotinic / Q000737:chemistry; D012995:Solubility; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D013696:Temperature
chemical_list: D020916:Conotoxins; D008978:Mollusk Venoms; D009842:Oligopeptides; D011978:Receptors, Nicotinic; C087686:alpha-conotoxin ImI