title: Effects of deletion and insertion of amino acids on the activity of HelaTx1, a scorpion toxin on potassium channels.
abstract: Four analogs of HelaTx1, a 25-mer peptide from scorpion venom, were synthesized by deleting its C-terminal hexapeptide fragment and N-terminal Ser residue and by inserting an amino acid in the middle part of the molecule. CD spectrum of HelaTx1(1-19) was almost superimposable to that of native HelaTx1. Functional characterization showed that HelaTx1(1-19) retained its inhibitory activity on Kv1.1 channel although 3 times less potent than HelaTx1, indicating that C-terminal part of HelaTx1 was not essential for its conformation and activity. Further deletion of N-terminal Ser residue and insertion of Ala in the middle part of the molecule affected the CD spectra and resulted in the decrease of activity.
authors.affiliation: Laboratory of Toxicology, University of Leuven (K.U. Leuven), Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, 3000, Leuven, Belgium.
authors.forename: Steve
authors.initials: S
authors.lastname: Peigneur
authors.affiliation: Department of Environmental Science, Fukuoka Women's University, Fukuoka, 813-8529, Japan.
authors.forename: Nao
authors.initials: N
authors.lastname: Esaki
authors.affiliation: Department of Environmental Science, Fukuoka Women's University, Fukuoka, 813-8529, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Yamaguchi
authors.affiliation: Laboratory of Toxicology, University of Leuven (K.U. Leuven), Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, 3000, Leuven, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Tytgat
authors.affiliation: Department of Environmental Science, Fukuoka Women's University, Fukuoka, 813-8529, Japan. Electronic address: sato@fwu.ac.jp.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Sato
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D055724:Electrophysiological Phenomena; D009865:Oocytes / Q000378:metabolism; D010455:Peptides / Q000138:chemical synthesis / Q000494:pharmacology*; D026902:Potassium Channel Blockers / Q000138:chemical synthesis / Q000494:pharmacology*; D015221:Potassium Channels / Q000378:metabolism*; D012604:Scorpion Venoms / Q000737:chemistry*; D012605:Scorpions / Q000737:chemistry*; D013329:Structure-Activity Relationship; D014981:Xenopus
chemical_list: D010455:Peptides; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D012604:Scorpion Venoms
keywords: Amino acid deletion; Amino acid insertion; HelaTx1; Scorpion toxin; Synthetic analog; Voltage-gated potassium channel