Delta-conotoxin GmVIA, a novel peptide from the venom of Conus gloriamaris.
A novel peptide toxin, delta-conotoxin GmVIA, was purified from the venom of Conus gloriamaris, a mollusc-hunting snail. It consists of 29 amino acids, including six Cys residues: [sequence: see text] The pattern of disulfide connectivity (4-19, 12-24, and 18-29) is the same as for the omega-conotoxins, which are Ca2+ channel ligands. However, the peptide does not compete with omega-conotoxin for binding to membrane preparations from frog, rat, and chick brain. Instead, initial electrophysiological results suggest that the peptide induces action potential broadening in molluscan neurons by slowing down Na+ current inactivation. Synthetic delta-conotoxin GmVIA was prepared by solid-phase methods and appeared identical in all respects to the natural material. The chromatographic behavior of native and reduced delta-conotoxins is quite remarkable, suggesting that the disulfides form a core which forces hydrophobic residues to point out toward the solvent.
Shon
K J
KJ
Department of Biology, University of Utah, Salt Lake City 84112.
Hasson
A
A
Spira
M E
ME
Cruz
L J
LJ
Gray
W R
WR
Olivera
B M
BM
D000595:Amino Acid Sequence; D000818:Animals; D001048:Aplysia / Q000166:cytology; D001921:Brain / Q000187:drug effects; D002645:Chickens; D020916:Conotoxins; D004220:Disulfides / Q000737:chemistry; D004594:Electrophysiology; D008566:Membranes / Q000187:drug effects; D008969:Molecular Sequence Data; D008978:Mollusk Venoms / Q000737:chemistry*; D009474:Neurons / Q000187:drug effects; D010456:Peptides, Cyclic / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D011898:Ranidae; D051381:Rats; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D012908:Snails; D015222:Sodium Channels / Q000187:drug effects; D013045:Species Specificity
D020916:Conotoxins; D004220:Disulfides; D008978:Mollusk Venoms; D010456:Peptides, Cyclic; D015222:Sodium Channels; C089621:delta-conotoxin GmVIA