Contryphan-Vn: a modulator of Ca2+-dependent K+ channels.
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.
Massilia
Gabriella Raybaudi
GR
Department of Biology, University Roma Tre, Viale Guglielmo Marconi 446, I-00146 Rome, Italy.
Eliseo
Tommaso
T
Grolleau
Francoise
F
Lapied
Bruno
B
Barbier
Julien
J
Bournaud
Roland
R
Molgó
Jordi
J
Cicero
Daniel Oscar
DO
Paci
Maurizio
M
Schininà
Maria Eugenia
ME
Ascenzi
Paolo
P
Polticelli
Fabio
F
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
D008978:Mollusk Venoms; D010456:Peptides, Cyclic; D015221:Potassium Channels; C102355:contryphan; D002118:Calcium