Contryphan-Vn: a modulator of Ca2+-dependent K+ channels

• Published in: Biochemical and biophysical research communications Vol. 303; no. 1; pp. 238 - 246
• Main Authors: Massilia, Gabriella Raybaudi, Eliseo, Tommaso, Grolleau, Francoise, Lapied, Bruno, Barbier, Julien, Bournaud, Roland, Molgó, Jordi, Cicero, Daniel Oscar, Paci, Maurizio, Schininà, Maria Eugenia, Ascenzi, Paolo, Polticelli, Fabio
• Format: Journal Article
• Language: English
• Published: United States Elsevier 28.03.2003
• Subjects: Animals; Calcium; Calcium - metabolism; Cell Line; Cell Line, Transformed; Chromaffin Cells; Chromaffin Cells - drug effects; Chromaffin Cells - metabolism; Electrophysiology; Humans; Life Sciences; Magnetic Resonance Spectroscopy; Models, Molecular; Mollusk Venoms; Neurons; Neurons - drug effects; Neurons - metabolism; Neurons and Cognition; Patch-Clamp Techniques; Peptides, Cyclic; Peptides, Cyclic - metabolism; Peptides, Cyclic - physiology; Potassium Channels; Potassium Channels - metabolism; Rats; Snails; Snails - metabolism; Time Factors; Rat fetal chromaffin cells; Solution structure; Cockroach dorsal unpaired median neurons; Contryphan-Vn; Ca2+-dependent K+ channels
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/S0006-291X(03)00331-0

Contryphan-Vn is a D-tryptophan-containing disulfide-constrained nonapeptide isolated from the venom of Conus ventricosus, the single Mediterranean cone snail species. The structure of the synthetic Contryphan-Vn has been determined by NMR spectroscopy. Unique among Contryphans, Contryphan-Vn displays the peculiar presence of a Lys-Trp dyad, reminiscent of that observed in several voltage-gated K(+) channel blockers. Electrophysiological experiments carried out on dorsal unpaired median neurons isolated from the cockroach (Periplaneta americana) nerve cord on rat fetal chromaffin cells indicate that Contryphan-Vn affects both voltage-gated and Ca(2+)-dependent K(+) channel activities, with composite and diversified effects in invertebrate and vertebrate systems. Voltage-gated and Ca(2+)-dependent K(+) channels represent the first functional target identified for a conopeptide of the Contryphan family. Furthermore, Contryphan-Vn is the first conopeptide known to modulate the activity of Ca(2+)-dependent K(+) channels.