Patent ID: 7527794

Claim:
A fusion polypeptide comprising (a) a first targeting polypeptide that binds heparan sulfate when said fusion polypeptide is permitted to contact cells or tissues, thereby localizing the fusion polypeptide to said heparan-sulfate rich cell or tissue surface; wherein said fusion polypeptide binds to heparin or to a heparan sulfate proteoglycan when measured in a conventional heparin-binding or heparan-sulfate binding assay, which first targeting polypeptide consists of: (i) a human neuregulin heparin-binding domain (N-HBD) the sequence of which is SEQ ID NO:1; or (ii) a heparin-binding fragment thereof the sequence of which is KWFKNGNELNRKNKPQNIKIQKKPGK (SEQ ID NO: 7); or (iii) a heparin binding fragment the sequence of which is K-x-x-K-x-x-x-x-x-x-R-K-x-K-x-x-x-x-K-x-x-K-K-x-x-K (SEQ ID NO:10), wherein x is any amino acid; and (b) a second targeted polypeptide P trg that is to be targeted and localized to the heparan sulfate-rich cell or tissue surface which second polypeptide is neuregulin (NRG), the extracellular domains of an erbB receptor, epidermal growth factor (EGF), a fibroblast growth factor (FGF), nerve growth factor (NGF) or a neurotrophic factor; wherein said fusion polypeptide, through the action of said P trg , has enhanced biological activity in stimulating or blocking a target receptor compared to native P trg or P trg not fused to said first targeting polypeptide.