title: Identification of amino acid sequences in fibrinogen gamma -chain and tenascin C C-terminal domains critical for binding to integrin alpha vbeta 3.
abstract: Integrin alpha(v)beta(3) recognizes fibrinogen gamma and alpha(E) chain C-terminal domains (gammaC and alpha(E)C) but does not require the gammaC dodecapeptide sequence HHLGGAKQAGDV(400-411) for binding to gammaC. We have localized the alpha(v)beta(3) binding sites in gammaC using gammaC-derived synthetic peptides. We found that two peptides GWTVFQKRLDGSV(190-202) and GVYYQGGTYSKAS(346-358) block the alpha(v)beta(3) binding to gammaC or alpha(E)C, block the alpha(v)beta(3)-mediated clot retraction, and induce the ligand-induced binding site 2 (LIBS2) epitope in alpha(v)beta(3). Neither peptide affects fibrinogen binding to alpha(IIb)beta(3). Scrambled or inverted peptides were not effective. These results suggest that the two gammaC-derived peptides directly interact with alpha(v)beta(3) and specifically block alpha(v)beta(3)-gammaC or alpha(E)C interaction. The two sequences are located next to each other in the gammaC crystal structure, although they are separate in the primary structure. Asp-199, Ser-201, Gln-350, Thr-353, Lys-356, Ala-357, and Ser-358 residues are exposed to the surface. This suggests that the two sequences are part of alpha(v)beta(3) binding sites in fibrinogen gammaC domain. We also found that tenascin C C-terminal fibrinogen-like domain specifically binds to alpha(v)beta(3). Notably, a peptide WYRNCHRVNLMGRYGDNNHSQGVNWFHWKG from this domain that includes the sequence corresponding to gammaC GVYYQGGTYSKAS(346-358) specifically binds to alpha(v)beta(3), suggesting that fibrinogen and tenascin C C-terminal domains interact with alpha(v)beta(3) in a similar manner.
authors.affiliation: Department of Vascular Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
authors.forename: K
authors.initials: K
authors.lastname: Yokoyama
authors.forename: H P
authors.initials: HP
authors.lastname: Erickson
authors.forename: Y
authors.initials: Y
authors.lastname: Ikeda
authors.forename: Y
authors.initials: Y
authors.lastname: Takada
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002478:Cells, Cultured; D006224:Cricetinae; D005340:Fibrinogen / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D019030:Receptors, Vitronectin / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D019063:Tenascin / Q000737:chemistry / Q000378:metabolism*
chemical_list: D019030:Receptors, Vitronectin; D011994:Recombinant Proteins; D019063:Tenascin; D005340:Fibrinogen