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

1. 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.

2. The fusion protein of claim 1 , wherein the first spacer consists of an amino acid sequence of from 6 to 16 amino acid residues.

3. The fusion protein of claim 1 , wherein the first spacer comprises amino acid residues selected from the group consisting of: glycine, threonine, arginine, serine, alanine, asparagine, glutamine, aspartic acid, proline, glutamic acid, and lysine.

4. The fusion protein of claim 1 , wherein the first spacer comprises amino acid residues selected from the group consisting of: glycine, serine, and alanine.

5. The fusion protein of claim 1 , wherein the first spacer is a GS5 spacer.

6. The fusion protein of claim 1 , wherein the targeting moiety comprises an amino acid sequence having at least 70% sequence identity to SEQ ID NO: 8.

7. The fusion protein of claim 1 consisting of an analgesic, single-chain polypeptide having at least 99% sequence identity with the sequence of SEQ ID NO: 32.

8. The fusion protein of claim 1 comprising the analgesic, single-chain polypeptide of SEQ ID NO: 32.

9. The fusion protein of claim 1 consisting of the analgesic, single-chain polypeptide of SEQ ID NO: 32.