title: Purification and sequence of a presynaptic peptide toxin from Conus geographus venom.
abstract: A novel toxin, omega-conotoxin (omega-CgTX), from the venom of the fish-eating marine mollusc Conus geographus has been purified and biochemically characterized. Recently, this omega-conotoxin has been shown to inhibit the voltage-activated entry of Ca2+, thus providing a potentially powerful probe for exploring the vertebrate presynaptic terminal [Kerr, L. M., & Yoshikami, D. (1984) Nature (London) 308, 282-284]. The toxin is a basic 27 amino acid peptide amide with three disulfide bridges. An unusual feature is a remarkable preponderance of hydroxylated amino acids. The sequence of omega-CgTx GVIA is Cys-Lys-Ser- Hyp-Gly5-Ser-Ser-Cys-Ser-Hyp10-Thr-Ser-Tyr-Asn-Cys15-C ys-Arg-Ser- Cys-Asn20-Hyp-Tyr-Thr-Lys-Arg25-Cys-Tyr-NH2.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D008970:Molecular Weight; D008978:Mollusk Venoms / Q000032:analysis / Q000302:isolation & purification*; D020866:omega-Conotoxin GVIA
chemical_list: D000596:Amino Acids; D008978:Mollusk Venoms; D020866:omega-Conotoxin GVIA