A novel M-superfamily conotoxin with a unique motif from Conus vexillum

Peptides. 2006 Apr;27(4):682-9. doi: 10.1016/j.peptides.2005.08.004. Epub 2005 Sep 21.


Cone snails are tropical marine mollusks that envenomate prey with a complex mixture of neuropharmacologically active compounds for the purpose of feeding and defence, each evolved to act in a highly specific manner on different parts of the nervous system. Here, we report the peptide purification, molecular cloning, chemical synthesis, and functional characterization of a structurally unique toxin isolated from the venom of Conus vexillum. The novel peptide, designated Vx2, was composed of 21 amino acid residues cross-linked by 3 disulfide bonds (WIDPSHYCCCGGGCTDDCVNC). Intriguingly, its mature peptide sequence shows low level of similarity with other identified conotoxins, and its unique motif (-CCCGGGC-) was not reported in other Conus peptides. However, its signal peptide sequence shares high similarity with those of the M-superfamily conotoxins. Hence, Vx2 could be classified into a new family of the M-superfamily.

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cloning, Molecular
  • Conotoxins / chemistry*
  • Conotoxins / classification*
  • Conotoxins / genetics
  • Conotoxins / isolation & purification
  • Conus Snail / chemistry*
  • Conus Snail / genetics
  • DNA, Complementary / genetics
  • Molecular Sequence Data
  • Protein Conformation
  • Sequence Homology, Amino Acid


  • Conotoxins
  • DNA, Complementary