title: OdK2, a Kv1.3 channel-selective toxin from the venom of the Iranian scorpion Odonthobuthus doriae.
abstract: The first Kv1.3 channel-selective toxin from the venom of the Iranian scorpion Odonthobuthus doriae (OdK2) was purified, sequenced and characterized physiologically. OdK2 consists of 38 amino acids, including six conserved cysteine and a C-terminal lysine residue, as revealed by the unique use of a quadrupole ion cyclotron resonance Fourier-transform mass spectrometer. Based on multiple sequence alignments, OdK2 was classified as alpha-KTX3.11. The pharmacological effects of OdK2 were studied on a panel of eight different cloned K(+) channels (vertebrate Kv1.1-Kv1.6, Shaker IR and hERG) expressed in Xenopus laevis oocytes. Interestingly, OdK2 selectively inhibits the currents through Kv1.3 channels with an IC50 value of 7.2+/-2.7nM.
authors.affiliation: Laboratory of Toxicology, University of Leuven, Onderwijs and Navorsing II, Herestraat 49, Leuven, Belgium.
authors.forename: Yousra
authors.initials: Y
authors.lastname: Abdel-Mottaleb
authors.forename: Thomas
authors.initials: T
authors.lastname: Vandendriessche
authors.forename: Elke
authors.initials: E
authors.lastname: Clynen
authors.forename: Bart
authors.initials: B
authors.lastname: Landuyt
authors.forename: Amir
authors.initials: A
authors.lastname: Jalali
authors.forename: Hossein
authors.initials: H
authors.lastname: Vatanpour
authors.forename: Liliane
authors.initials: L
authors.lastname: Schoofs
authors.forename: Jan
authors.initials: J
authors.lastname: Tytgat
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004553:Electric Conductivity; D051664:Kv1.3 Potassium Channel / Q000037:antagonists & inhibitors*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009865:Oocytes / Q000187:drug effects; D026902:Potassium Channel Blockers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D017434:Protein Structure, Tertiary; D012604:Scorpion Venoms / Q000737:chemistry*; D012605:Scorpions / Q000737:chemistry*; D016415:Sequence Alignment; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014982:Xenopus laevis
chemical_list: D051664:Kv1.3 Potassium Channel; D026902:Potassium Channel Blockers; D012604:Scorpion Venoms