Fusion proteins comprising a non-cytotoxic protease, a translocation domain, and a targeting moiety that binds a galanin receptor and methods for treating, preventing or ameliorating pain using such fusion proteins

A fusion protein comprising an analgesic, non-cytotoxic single chain polypeptide, the polypeptide comprising:

• a non-cytotoxic protease capable of cleaving a protein of the exocytic fusion apparatus of a nociceptive sensory afferent;
• a targeting moiety that binds to a binding site on the nociceptive sensory afferent, wherein the binding site is capable of being incorporated into an endosome within the nociceptive sensory afferent;
• a protease cleavage site;
• a translocation domain capable of translocating the protease from within the endosome, across the endosomal membrane, and into the cytosol of the nociceptive sensory afferent;
• a first spacer located between the non-cytotoxic protease and the protease cleavage site, the first spacer comprising an amino acid sequence of from 4 to 25 amino acid residues;
• and
• a second spacer located between the targeting moiety and the translocation domain, the second spacer comprising an amino acid sequence of from 4 to 35 amino acid residues;
• wherein:
• the protease cleavage site is located between the non-cytotoxic protease and the targeting moiety;
• the targeting moiety is located between the protease cleavage site and the translocation domain;
• and
• the analgesic, single-chain polypeptide has at least 99% sequence identity to SEQ ID NO:
• 32.