Mass spectrometric identification of bromotryptophan containing conotoxin sequences from the venom of C. amadis

Toxicon. 2018 Mar 15:144:68-74. doi: 10.1016/j.toxicon.2018.02.005. Epub 2018 Feb 13.


Four 30 residue conotoxin have been identified from the venom of C. amadis. MS/MS analysis of crude venom subjected to global reduction/alkylation yielded fragmentation patterns, which permitted searching and matching with a database of putative mature toxin sequences obtained from transcriptomic analysis. Of the four sequences identified, Am3408(Am6.1b), Am3452(Am6.1c), Am3136(Am6.2a) and Am3214(Am6.2b), three contain bromotryptophan residues, while an additional post translational modification, gamma carboxylation of glutamic acid, is present in Am3408(Am6.1b)/3452(Am6.1c). The conotoxins belong to the O1/O2 gene superfamily and possess cysteine framework VI/VII. While, the cysteine patterns show a similarity to omega conotoxins, the three C. amadis peptides are highly negatively charged and possess a significant content of hydrophobic residues.

Keywords: Conotoxins; Conus venom; Mass spectrometry and bromotryptophan; Transcriptome.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Conotoxins / chemistry*
  • Conus Snail / chemistry
  • Peptides / chemistry*
  • Peptides / isolation & purification
  • Protein Processing, Post-Translational
  • Tandem Mass Spectrometry
  • Transcriptome
  • Tryptophan / chemistry


  • Conotoxins
  • Peptides
  • Tryptophan