title: Proteomic analysis of the venom and characterization of toxins specific for Na+ - and K+ -channels from the Colombian scorpion Tityus pachyurus.
abstract: The Colombian scorpion Tityus pachyurus is toxic to humans and is capable of producing fatal accidents, but nothing is known about its venom components. This communication reports the separation of at least 57 fractions from the venom by high performance liquid chromatography. From these, at least 104 distinct molecular weight compounds were identified by mass spectrometry analysis. The complete amino acid sequences of three peptides were determined and the partial sequences of three others were also identified. Electrophysiological experiments conducted with ion-channels expressed heterologously on Sf9 cells showed the presence of a potent Shaker B K(+)-channel blocker. This peptide (trivial name Tpa1) contains 23 amino acid residues closely packed by three disulfide bridges with a molecular mass of 2,457 atomic mass units. It is the third member of the sub-family 13, for which the systematic name is proposed to be alpha-KTx13.3. The mice assay showed clearly the presence of toxic peptides to mammals. One of them named Tpa2, containing 65 amino acid residues with molecular mass of 7,522.5 atomic mass units, is stabilized by four disulfide bridges. It was shown to modify the Na(+)-currents of F-11 and TE671 cells in culture, similar to the beta scorpion toxins. These results demonstrate the presence of toxic peptides in the venom of T. pachyurus and confirm that accidents with this species of scorpion should be considered an important human hazard in Colombia.
authors.affiliation: Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Avenida Universidad, 2001, Apartado Postal 510-3, Cuernavaca 62210, Mexico.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Barona
authors.forename: Cesar V F
authors.initials: CV
authors.lastname: Batista
authors.forename: Fernando Z
authors.initials: FZ
authors.lastname: Zamudio
authors.forename: Froylan
authors.initials: F
authors.lastname: Gomez-Lagunas
authors.forename: Enzo
authors.initials: E
authors.lastname: Wanke
authors.forename: Rafael
authors.initials: R
authors.lastname: Otero
authors.forename: Lourival D
authors.initials: LD
authors.lastname: Possani
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D066298:In Vitro Techniques; D007928:Lethal Dose 50; D051379:Mice; D008969:Molecular Sequence Data; D026902:Potassium Channel Blockers / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity; D015221:Potassium Channels / Q000187:drug effects*; D040901:Proteomics; D012604:Scorpion Venoms / Q000737:chemistry* / Q000235:genetics / Q000633:toxicity*; D012605:Scorpions / Q000737:chemistry / Q000235:genetics / Q000472:pathogenicity; D017386:Sequence Homology, Amino Acid; D051637:Shaker Superfamily of Potassium Channels / Q000037:antagonists & inhibitors; D026941:Sodium Channel Blockers / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity; D015222:Sodium Channels / Q000187:drug effects*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D026902:Potassium Channel Blockers; D015221:Potassium Channels; D012604:Scorpion Venoms; D051637:Shaker Superfamily of Potassium Channels; D026941:Sodium Channel Blockers; D015222:Sodium Channels