Polypeptides of the neuregulin (NRG) heparin binding domain (N-HBD) and
nucleic acids coding therefor are disclosed. In particular, fusion
polypeptides are produced that comprise, as a targeting structure, a
N-HBD polypeptide, fragment, homologue or functional derivative and a
protein to be targeted. This is fused to a polypeptide or peptide being
targeted (Ptrg) to cell surfaces rich in heparan sulfate proteoglycans to
either activate or inhibit interactions at tyrosine kinase receptors.
Such products are used to treat diseases or conditions where either
agonism or antagonism at tyrosine kinase receptors has beneficial
effects, including cancer and a multitude of diseases of the nervous
system.
