title: 1H-NMR signal assignments and secondary structure analysis of martentoxin.
abstract: Martentoxin is a peptide of 37 amino acid residues purified from the venom of the Chinese scorpion Buthus martensi Karch, which has been demonstrated to be an inhibitor of voltage-dependent sodium channel and voltage-dependent delayed rectifier potassium channel. To elucidate the molecular mechanism of this interaction, the structure of martentoxin was studied by 2D-NMR. The secondary structure of martentoxin consists of a triple-stranded beta-sheet connected to a alpha-helical structure. This helix encompasses 10 residues from Ser11 to Lys20. The three strands of beta-sheet probably comprise residues Gly2-Asp5, Q27-N30 and Glu33-Cys36, Cys30-Asn33 with a type I'beta turn centered on Asn31-Asn32. The results indicate that martentoxin possesses the conserved beta alpha beta beta structure of all the potassium channel toxins.
authors.affiliation: Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
authors.forename: Y-H
authors.initials: YH
authors.lastname: Wang
authors.forename: Z-Y
authors.initials: ZY
authors.lastname: Cao
authors.forename: W-Y
authors.initials: WY
authors.lastname: He
authors.forename: X-Z
authors.initials: XZ
authors.lastname: Yan
authors.forename: X
authors.initials: X
authors.lastname: Liu
authors.forename: H-Y
authors.initials: HY
authors.lastname: Liu
authors.forename: X-T
authors.initials: XT
authors.lastname: Liang
authors.forename: D-Q
authors.initials: DQ
authors.lastname: Yu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D012604:Scorpion Venoms / Q000737:chemistry*; D012605:Scorpions / Q000737:chemistry*
chemical_list: D012604:Scorpion Venoms; C471035:martentoxin, Buthus martensi