#$%^&*AU2006236006B220120906.pdf#####P DPEWmmxSpwifcdgsCyd0zod alhI4,ooobn ppW. - wwd-4&-IS/I ItAO ABSTRACT This invention relates to synthetically cyplised a-conotoxin peptide having an aide cyclised backbone such that the peptide has no free N- or C- terminus, said peptide having the ability to inhibit a nicotinic acetylcholine receptor and comprising four cysteine residues bonded in pairs to form two disulfide bonds, wherein the N-terminus of the corresponding linear/non-cyclised conotoxin peptide is linked to the C-terminus by a peptide linker of such that between six and eight amino acid residues span the distance between cysteine residues I and IV.