OdK2, a Kv1.3 channel-selective toxin from the venom of the Iranian scorpion Odonthobuthus doriae.
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.
Abdel-Mottaleb
Yousra
Y
Laboratory of Toxicology, University of Leuven, Onderwijs and Navorsing II, Herestraat 49, Leuven, Belgium.
Vandendriessche
Thomas
T
Clynen
Elke
E
Landuyt
Bart
B
Jalali
Amir
A
Vatanpour
Hossein
H
Schoofs
Liliane
L
Tytgat
Jan
J
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
D051664:Kv1.3 Potassium Channel; D026902:Potassium Channel Blockers; D012604:Scorpion Venoms