Abstract
A novel peptide toxin, δ-conotoxin GmVIA, was purified from the venom of Conus gloriamaris, a mollusc-hunting snail. It consists of 29 amino acids, including six Cys residues: [formula omitted] The pattern of disulfide connectivity (4–19, 12–24, and 18–29) is the same as for the ω-conotoxins, which are Ca2+ channel ligands. However, the peptide does not compete with ω-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 δ-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 δ-conotoxins is quite remarkable, suggesting that the disulfides form a core which forces hydrophobic residues to point out toward the solvent.
Original language | English |
---|---|
Pages (from-to) | 11420-11425 |
Number of pages | 6 |
Journal | Biochemistry |
Volume | 33 |
Issue number | 38 |
DOIs | |
State | Published - 1 Sep 1994 |