Abstract: Fibroblast growth factor(FGF) is known to bind to its cell-surface receptor in a heparin dependent manner. By mimicking this in vivo process, we designed a novel screening strategy for the identification of FGFligands that bind to the receptor binding region of FGF. After three cycles of selection, the phage recovery increased from 3.1×10^-4% to 3.3×10^-3%. The DNA inserts of phage clones were sequenced and a group of related peptide sequences were identified. Compared with a key FGF binding loop on the receptor (aa.342～357), these peptide sequences show similarities at several positions. Further ELISA experiment demonstrates that some phage containing these sequences can specifically bind to FGF. And cell proliferation assay suggest that the synthesized peptide can strongly inhibit the mitogenic activity of a FGF. Therefore, these peptides may specifically block the receptor binding to FGFand have the potential of becoming therapeutic agents as FGF antagonists.

Key words: Fibroblast growth factor, Phage, Peptide library, Heparin, Selection