title: The scorpion toxin Bot IX is a potent member of the α-like family and has a unique N-terminal sequence extension.
abstract: We report the detailed chemical, immunological and pharmacological characterization of the α-toxin Bot IX from the Moroccan scorpion Buthus occitanus tunetanus venom. Bot IX, which consists of 70 amino acids, is a highly atypical toxin. It carries a unique N-terminal sequence extension and is highly lethal in mice. Voltage clamp recordings on oocytes expressing rat Nav1.2 or insect BgNav1 reveal that, similar to other α-like toxins, Bot IX inhibits fast inactivation of both variants. Moreover, Bot IX belongs to the same structural/immunological group as the α-like toxin Bot I. Remarkably, radioiodinated Bot IX competes efficiently with the classical α-toxin AaH II from Androctonus australis, and displays one of the highest affinities for Nav channels.
authors.affiliation: Aix Marseille Université, CNRS, CRN2M, UMR7286, PFRN-CAPM, Marseille, France.
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Martin-Eauclaire
authors.affiliation: Department of Physiology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Juan
authors.initials: J
authors.lastname: Salvatierra
authors.forename: Pascal
authors.lastname: Mansuelle
authors.affiliation: Department of Physiology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.|Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Frank
authors.initials: F
authors.lastname: Bosmans
authors.affiliation: Aix Marseille Université, CNRS, CRN2M, UMR7286, PFRN-CAPM, Marseille, France. pierre-edouard.bougis@univ-amu.fr.
authors.forename: Pierre E
authors.initials: PE
authors.lastname: Bougis
mesh_terms: D000818:Animals; D002460:Cell Line; D003058:Cockroaches; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D062551:NAV1.2 Voltage-Gated Sodium Channel / Q000378:metabolism; D000072417:Protein Domains; D051381:Rats; D012604:Scorpion Venoms / Q000737:chemistry / Q000494:pharmacology / Q000633:toxicity*; D026941:Sodium Channel Blockers / Q000737:chemistry / Q000494:pharmacology / Q000633:toxicity*; D014981:Xenopus
chemical_list: D062551:NAV1.2 Voltage-Gated Sodium Channel; C568253:Scn2A protein, rat; D012604:Scorpion Venoms; D026941:Sodium Channel Blockers; C000618498:alpha-toxin IX, Buthus occitanus tunetanus
keywords: Nav channel; scorpion toxin; α-like toxin