Patent ID: 7994123

Claim:
A fusion polypeptide comprising (a) a targeting polypeptide that comprises a human neuregulin heparin binding domain (N-HBD); and (b) fused directly C-terminally to the N-HBD, a peptide linker or spacer (S) that is the natural amino acid spacer of human neuregulin, the sequence of which is residues 131-195 of SEQ ID NO: 14, and (c) fused directly C-terminally to S, a targeted polypeptide that comprises human erbB4 receptor extracellular domain (B4-ECD) that is to be targeted and localized to the heparan sulfate-rich cell or tissue surface; wherein (i) said fusion polypeptide binds heparan sulfate when said fusion polypeptide is permitted to contact cells or tissues, thereby localizing the B4-ECD of (c) to heparan sulfate-rich cell or tissue surface; and (ii) said fusion polypeptide has enhanced biological activity in blocking a target receptor compared to native human B4-ECD or human B4-ECD that is not fused to said S and said human N-HBD.