Tyr13 is essential for the activity of omega-conotoxin MVIIA and GVIA, specific N-type calcium channel blockers

Biochem Biophys Res Commun. 1995 Jan 17;206(2):449-54. doi: 10.1006/bbrc.1995.1063.


Two analogs of omega-conotoxin MVIIA, a 25mer peptide neurotoxin, were synthesized by replacing Lys2 or Tyr13 with Ala. The activities of synthetic analogs were estimated from the inhibitory action on 125I-omega-conotoxin GVIA binding to chick brain synaptic plasma membranes. As in the case of omega-conotoxin GVIA, replacement of Tyr13 resulted in an enormous reduction in activity. In contrast, substitution of Ala for Lys2 gave only a small effect. These results indicate that Tyr13 is a critical amino acid of omega-conotoxin MVIIA and GVIA for blocking N-type calcium channel function.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Brain / metabolism
  • Calcium Channel Blockers / metabolism
  • Calcium Channel Blockers / pharmacology*
  • Chickens
  • Circular Dichroism
  • Kinetics
  • Lysine
  • Molecular Sequence Data
  • Peptides / chemical synthesis
  • Peptides / chemistry
  • Peptides / metabolism
  • Peptides / pharmacology*
  • Peptides, Cyclic / chemical synthesis
  • Peptides, Cyclic / chemistry
  • Peptides, Cyclic / pharmacology
  • Protein Conformation
  • Synaptic Membranes / metabolism
  • Tyrosine*
  • omega-Conotoxin GVIA
  • omega-Conotoxins*


  • Calcium Channel Blockers
  • Peptides
  • Peptides, Cyclic
  • omega-Conotoxins
  • Tyrosine
  • ziconotide
  • omega-Conotoxin GVIA
  • Lysine