title: A novel toxin from the venom of the scorpion Tityus trivittatus, is the first member of a new alpha-KTX subfamily.
abstract: The first example of a new sub-family of toxins (alpha-KTx20.1) from the scorpion Tityus trivittatus was purified, sequenced and characterized physiologically. It has 29 amino acid residues, three disulfide bridges assumed to adopt the cysteine-stabilized alpha/beta scaffold with a pI value of 8.98. The sequence identities with all the other known alpha-KTx are less than 40%. Its effects were verified using seven different cloned K(+) channels (vertebrate Kv1.1-1.5, Shaker IR and hERG) expressed in Xenopus leavis oocytes. The toxin-induced effects show large differences among the different K(+) channels and a preference towards Kv1.3 (EC50=7.9+/-1.4 nM).
authors.affiliation: Laboratory of Toxicology, University of Leuven, Onderwijs and Navorsing II, Herestraat 49, Postbus 922, 3000 Leuven, Belgium.
authors.forename: Yousra
authors.initials: Y
authors.lastname: Abdel-Mottaleb
authors.forename: Fredy V
authors.initials: FV
authors.lastname: Coronas
authors.forename: Adolfo R
authors.initials: AR
authors.lastname: de Roodt
authors.forename: Lourival D
authors.initials: LD
authors.lastname: Possani
authors.forename: Jan
authors.initials: J
authors.lastname: Tytgat
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D008969:Molecular Sequence Data; D026902:Potassium Channel Blockers / Q000737:chemistry / Q000378:metabolism; D015221:Potassium Channels / Q000378:metabolism; D012604:Scorpion Venoms / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D012605:Scorpions / Q000737:chemistry*; D016415:Sequence Alignment
chemical_list: D026902:Potassium Channel Blockers; D015221:Potassium Channels; D012604:Scorpion Venoms; C508779:alpha-KTx20.1 protein, Tityus trivittatus