title: Contryphan-Vn: a modulator of Ca2+-dependent K+ channels.
abstract: 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.
authors.affiliation: Department of Biology, University Roma Tre, Viale Guglielmo Marconi 446, I-00146 Rome, Italy.
authors.forename: Gabriella Raybaudi
authors.initials: GR
authors.lastname: Massilia
authors.forename: Tommaso
authors.initials: T
authors.lastname: Eliseo
authors.forename: Francoise
authors.initials: F
authors.lastname: Grolleau
authors.forename: Bruno
authors.initials: B
authors.lastname: Lapied
authors.forename: Julien
authors.initials: J
authors.lastname: Barbier
authors.forename: Roland
authors.initials: R
authors.lastname: Bournaud
authors.forename: Jordi
authors.initials: J
authors.lastname: Molgó
authors.forename: Daniel Oscar
authors.initials: DO
authors.lastname: Cicero
authors.forename: Maurizio
authors.initials: M
authors.lastname: Paci
authors.forename: Maria Eugenia
authors.initials: ME
authors.lastname: Schininà
authors.forename: Paolo
authors.initials: P
authors.lastname: Ascenzi
authors.forename: Fabio
authors.initials: F
authors.lastname: Polticelli
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D002461:Cell Line, Transformed; D019439:Chromaffin Cells / Q000187:drug effects / Q000378:metabolism; D004594:Electrophysiology; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008978:Mollusk Venoms; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D018408:Patch-Clamp Techniques; D010456:Peptides, Cyclic / Q000378:metabolism* / Q000502:physiology*; D015221:Potassium Channels / Q000378:metabolism*; D051381:Rats; D012908:Snails / Q000378:metabolism; D013997:Time Factors
chemical_list: D008978:Mollusk Venoms; D010456:Peptides, Cyclic; D015221:Potassium Channels; C102355:contryphan; D002118:Calcium