STRUCTURAL FEATURES OF FIBRONECTIN SYNTHETIC PEPTIDE FN-C H II, RESPONSIBLE FOR CELL-ADHESION, NEURITE EXTENSION, AND HEPARAN-SULFATE BINDING/

FN-C/H II (KNNQKSEPLIGRKKT), a heparin-binding peptide derived from th e COOH-terminal heparin-binding domain of fibronectin, mediates cell a dhesion for a variety of cell types and promotes neurite out-growth. B y systematic amino acid substitution of synthetic peptide analogues of FN-C/H II, the basic structural features necessary for activity have been identified in the COOH-terminal residues LIGRKK. This biologicall y ''active'' sequence has been located in several other heparin/hepara n sulfate-binding proteins and may represent a potential binding motif for sulfated polyanions. NMR structural studies indicate that the COO H-terminal segment of FN-C/H II displays significant multiple-turn or helix-like character suggesting that the RKK sequence may lie on the s ame surface of the protein, as opposed to alternating in an extended c hain motif.