title: Kbot55, purified from Buthus occitanus tunetanus venom, represents the first member of a novel α-KTx subfamily.
abstract: Kbot55 is a 39 amino acid peptide isolated from the venom of the Tunisian scorpion Buthus occitanus tunetanus. This peptide is cross-linked by 3 disulfide bridges and has a molecular mass of 4128.65Da. Kbot55 is very low represented in the venom and thus represents a challenge for biochemical characterization. In this study, Kbot55 has been subjected to a screening on ion channels expressed in Xenopus laevis oocytes. It was found that Kbot55 targets voltage-gated potassium channels with high affinity. Kbot55 shows very low amino acid identity with other scorpion potassium toxins and therefore was considered a bona fide novel type of scorpion toxin. Sequence alignment analysis indicated that Kbot55 is the first representative of the new α-Ktx31 subfamily and therefore was classified as α-Ktx31.1.
authors.affiliation: Laboratoire des Venins et Molécules Thérapeutiques, Institut Pasteur de Tunis, 13 Place Pasteur, BP-74, 1002 Tunis, Tunisia.
authors.forename: Rym
authors.initials: R
authors.lastname: ElFessi-Magouri
authors.affiliation: Toxicology & Pharmacology, University of Leuven (K.U. Leuven), Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, B-3000 Leuven, Belgium.
authors.forename: Steve
authors.initials: S
authors.lastname: Peigneur
authors.affiliation: Laboratoire des Venins et Molécules Thérapeutiques, Institut Pasteur de Tunis, 13 Place Pasteur, BP-74, 1002 Tunis, Tunisia.
authors.forename: Oussema
authors.initials: O
authors.lastname: Khamessi
authors.affiliation: Laboratoire des Venins et Molécules Thérapeutiques, Institut Pasteur de Tunis, 13 Place Pasteur, BP-74, 1002 Tunis, Tunisia.
authors.forename: Najet
authors.initials: N
authors.lastname: Srairi-Abid
authors.affiliation: Laboratoire des Venins et Molécules Thérapeutiques, Institut Pasteur de Tunis, 13 Place Pasteur, BP-74, 1002 Tunis, Tunisia.
authors.forename: Mohamed
authors.initials: M
authors.lastname: ElAyeb
authors.affiliation: Toxicology & Pharmacology, University of Leuven (K.U. Leuven), Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, B-3000 Leuven, Belgium.
authors.forename: Bea Garcia
authors.initials: BG
authors.lastname: Mille
authors.affiliation: Toxicology & Pharmacology, University of Leuven (K.U. Leuven), Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, B-3000 Leuven, Belgium.
authors.forename: Eva
authors.initials: E
authors.lastname: Cuypers
authors.affiliation: Toxicology & Pharmacology, University of Leuven (K.U. Leuven), Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, B-3000 Leuven, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Tytgat
authors.affiliation: Laboratoire des Venins et Molécules Thérapeutiques, Institut Pasteur de Tunis, 13 Place Pasteur, BP-74, 1002 Tunis, Tunisia. Electronic address: riadh.kharrat@pasteur.rns.tn.
authors.forename: Riadh
authors.initials: R
authors.lastname: Kharrat
mesh_terms: D000818:Animals; D004220:Disulfides / Q000737:chemistry; D008297:Male; D008810:Mice, Inbred C57BL; D008970:Molecular Weight; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism; D018408:Patch-Clamp Techniques; D010455:Peptides / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D024642:Potassium Channels, Voltage-Gated / Q000037:antagonists & inhibitors / Q000378:metabolism; D012604:Scorpion Venoms / Q000737:chemistry*; D012605:Scorpions / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D018675:Toxicity Tests / Q000379:methods; D014982:Xenopus laevis
chemical_list: D004220:Disulfides; D010455:Peptides; D024642:Potassium Channels, Voltage-Gated; D012604:Scorpion Venoms; C000614675:alpha-Ktx31.1 toxin, Buthus
keywords: Disulfide bridges; Peptide; Scorpion envenomation; Scorpion potassium toxins; α-KTx31 subfamily