Patent ID: 7507717

Claim:
An isolated, synthetic or recombinant χ-conotoxin peptide having the ability to inhibit a neuronal noradrenaline transporter comprising the following sequence of amino acids: (SEQ ID NO. 3) Cys Cys Gly Tyr Lys Leu Cys Xaa5 Xaa6 Cys wherein the peptide has one disulfide bond between the cysteines at positions 1 and 10 of SEQ ID NO: 3 and a second disulfide bond between the cysteines at positions 2 and 7 of SEQ ID NO: 3, where Xaa5 and Xaa6 represent any amino acid residue except Cys; or a sequence in which at least one of Tyr or Leu is subject to side chain modification, wherein said side chain modification for Tyr is a substitution of Tyr with MeY, and said side chain modification for Leu is a substitution of Leu with Hle or Nle; with the proviso that the peptide is not χ-MrIA, χ-MrIB, Mar2, CMrVIA, Bn1.5, Mr1.3 or Au1.4; or a salt, ester, amide, prodrug or cyclised derivative thereof.