A novel conotoxin inhibiting vertebrate voltage-sensitive potassium channels
| Autor: | André Ménez, Jan Tytgat, Filipina Sotto, Silke Kauferstein, Isabelle Huys, Reto Stöcklin, Dietrich Mebs, Hung Lamthanh |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Patch-Clamp Techniques
Potassium Channels Molecular Sequence Data Snails Dendrotoxin Peptide Toxicology complex mixtures Xenopus laevis Conus Potassium Channel Blockers Animals Humans Amino Acid Sequence RNA Messenger Conotoxin Peptide sequence chemistry.chemical_classification Kv1.3 Potassium Channel Dose-Response Relationship Drug biology Edman degradation Calcium Channel Blockers biology.organism_classification Rats Amino acid Conus virgo Electrophysiology chemistry Biochemistry Potassium Channels Voltage-Gated Conotoxins Kv1.1 Potassium Channel Ion Channel Gating |
| Zdroj: | Toxicon. 42:43-52 |
| ISSN: | 0041-0101 |
| DOI: | 10.1016/s0041-0101(03)00099-0 |
| Popis: | Toxins from cone snail ( Conus species) venoms are multiple disulfide bonded peptides. Based on their pharmacological target (ion channels, receptors) and their disulfide pattern, they have been classified into several toxin families and superfamilies. Here, we report a new conotoxin, which is the first member of a structurally new superfamily of Conus peptides and the first conotoxin affecting vertebrate K + channels. The new toxin, designated conotoxin ViTx, has been isolated from the venom of Conus virgo and comprises a single chain of 35 amino acids cross-linked by four disulfide bridges. Its amino acid sequence (SRCFPPGIYCTSYLPCCWGICCSTCRNVCHLRIGK) was partially determined by Edman degradation and deduced from the nucleotide sequence of the toxin cDNA. Nucleic acid sequencing also revealed a prepropeptide comprising 67 amino acid residues and demonstrated a posttranslational modification of the protein by releasing a six-residue peptide from the C-terminal. Voltage clamp studies on various ion channels indicated that the toxin inhibits the vertebrate K + channels Kv1.1 and Kv1.3 but not Kv1.2. The chemically synthesized product exhibited the same physiological activity and identical molecular mass (3933.7 Da) as the native toxin. |
| Databáze: | OpenAIRE |
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