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.

[1]  D. Yoshikami,et al.  Novel alpha- and omega-conotoxins from Conus striatus venom. , 1992, Biochemistry.

[2]  G. Whitesides,et al.  SELECTIVE REDUCTION OF DISULFIDES BY TRIS(2-CARBOXYETHYL) PHOSPHINE , 1991 .

[3]  B. Olivera,et al.  Conus Peptides as Chemical Probes for Receptors and Ion Channels , 1993 .

[4]  S. Woodward,et al.  Diversity of Conus neuropeptides. , 1990, Science.

[5]  S. Schacher,et al.  Neurite regeneration by Aplysia neurons in dissociated cell culture: modulation by Aplysia hemolymph and the presence of the initial axonal segment , 1983, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[6]  B. Olivera,et al.  Calcium channel antagonists. Omega-conotoxin defines a new high affinity site. , 1986, The Journal of biological chemistry.

[7]  M. Spira,et al.  Alteration of Sodium Currents by New Peptide Toxins From the Venom of a Molluscivorous Conus Snail , 1993, The European journal of neuroscience.

[8]  M. Spira,et al.  Mollusc-specific toxins from the venom of Conus textile neovicarius. , 1991, European journal of biochemistry.

[9]  J. Haack,et al.  A new Conus peptide ligand for Ca channel subtypes , 1993, Neuropharmacology.

[10]  S. Woodward,et al.  A molluscivorous Conus toxin: conserved frameworks in conotoxins. , 1989, Biochemistry.

[11]  J. McIntosh,et al.  Neuronal calcium channel antagonists. Discrimination between calcium channel subtypes using omega-conotoxin from Conus magus venom. , 1987, Biochemistry.

[12]  D. Gordon,et al.  A new neurotoxin receptor site on sodium channels is identified by a conotoxin that affects sodium channel inactivation in molluscs and acts as an antagonist in rat brain. , 1994, The Journal of biological chemistry.

[13]  W. Gray Disulfide structures of highly bridged peptides: A new strategy for analysis , 1993, Protein science : a publication of the Protein Society.

[14]  J. McIntosh,et al.  Purification and sequence of a presynaptic peptide toxin from Conus geographus venom. , 1984, Biochemistry.

[15]  B. Bean,et al.  A new conus peptide ligand for mammalian presynaptic Ca2+ channels , 1992, Neuron.