The present invention is directed to .beta.-superfamily conotoxin peptides, derivatives or pharmaceutically acceptable salts thereof. The present invention is further directed to the use of this peptide, derivatives thereof and pharmaceutically acceptable salts thereof for the treatment of disorders associated with voltage-gated ion channels, ligand gated channels and other receptors. The invention is further directed to nucleic acid sequences encoding the .beta.-superfamily conotoxin peptides and encoding .beta.-superfamily conotoxin propeptides, as well as the .beta.-superfamily conotoxin propeptides.