title: Purification, crystallization and initial structural solution of a new alpha-like toxin with cardiac toxicity from scorpion Buthus martensii Karsch.
abstract: An alpha-like toxin named BmK M7 active on both mammals and insects has been purified from the venom of scorpion Buthus martensii Karsch (BmK) recently. The electrophysiological experiments showed that M7 can bind to human cardiac Na+-channel and modify its normal properties, hence can be considered as a cardiotoxin. Single crystals of M7 have been obtained by hanging-drop vapor diffusion method using ammonium sulfate as precipitant in Tris-HCl buffer at pH 8.5. A data set to 1.40 A resolution was collected using synchrotron radiation and CCD detector in Photon Factory in Japan. Data analysis showed that the crystals belonged to space group P3(1)21/P3(1)21, with cell dimensions a=b=32.76 A, c=176.82 A. Assuming two molecules per asymmetric unit, the Vm value is 1.92 A3/Da. The initial structural analysis was carried out by molecular replacement, which showed the correct space group (P3(1)21), and the orientations and positions of the two molecules in the asymmetric unit.
authors.affiliation: Center for Molecular Biology, Institute of Biophysics, Chinese Academy of Sciences, 100101 Beijing China.
authors.forename: Rong-Jin
authors.initials: RJ
authors.lastname: Guan
authors.forename: Xiao-Lin
authors.initials: XL
authors.lastname: He
authors.forename: Miao
authors.initials: M
authors.lastname: Wang
authors.lastname: Ye-Xiang
authors.forename: Gen-Pei
authors.initials: GP
authors.lastname: Li
authors.forename: Da-Cheng
authors.initials: DC
authors.lastname: Wang
mesh_terms: D000818:Animals; D001681:Biological Assay; D003460:Crystallization; D018360:Crystallography, X-Ray; D006321:Heart / Q000187:drug effects*; D006793:Houseflies / Q000187:drug effects; D007814:Larva / Q000187:drug effects; D012604:Scorpion Venoms / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D026941:Sodium Channel Blockers
chemical_list: C471082:BmK M7 toxin, Buthus martensii; D012604:Scorpion Venoms; D026941:Sodium Channel Blockers