title: Chimeric peptides of statherin and osteopontin that bind hydroxyapatite and mediate cell adhesion.
abstract: Extracellular matrix proteins play key roles in controlling the activities of osteoblasts and osteoclasts in bone remodeling. These bone-specific extracellular matrix proteins contain amino acid sequences that mediate cell adhesion, and many of the bone-specific matrix proteins also contain acidic domains that interact with the mineral surface and may orient the signaling domains. Here we report a fusion peptide design that is based on this natural approach for the display of signaling peptide sequences at biomineral surfaces. Salivary statherin contains a 15-amino acid hydroxyapatite binding domain (N15) that is loosely helical in solution. To test whether N15 can serve to orient active peptide sequences on hydroxyapatite, the RGD and flanking residues from osteopontin were fused to the C terminus. The fusion peptides bound tightly to hydroxyapatite, and the N15-PGRGDS peptide mediated the dose-dependent adhesion of Moalpha(v) melanoma cells when immobilized on the hydroxyapatite surface. Experiments with an integrin-sorted Moalpha(v) subpopulation demonstrated that the alpha(v)beta(3) integrin was the primary receptor target for the fusion peptide. Solid state NMR experiments showed that the RGD portion of the hydrated fusion peptide is highly dynamic on the hydroxyapatite surface. This fusion peptide framework may thus provide a straightforward design for immobilizing bioactive sequences on hydroxyapatite for biomaterials, tissue engineering, and vaccine applications.
authors.affiliation: Department of Bioengineering and Department of Chemistry, University of Washington, Seattle, Washington 98195, USA.
authors.forename: M
authors.initials: M
authors.lastname: Gilbert
authors.forename: W J
authors.initials: WJ
authors.lastname: Shaw
authors.forename: J R
authors.initials: JR
authors.lastname: Long
authors.forename: K
authors.initials: K
authors.lastname: Nelson
authors.forename: G P
authors.initials: GP
authors.lastname: Drobny
authors.forename: C M
authors.initials: CM
authors.lastname: Giachelli
authors.forename: P S
authors.initials: PS
authors.lastname: Stayton
mesh_terms: D000327:Adsorption; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D002448:Cell Adhesion / Q000187:drug effects*; D002942:Circular Dichroism; D017886:Durapatite / Q000378:metabolism*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008545:Melanoma / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism; D053495:Osteopontin; D010446:Peptide Fragments / Q000494:pharmacology; D011485:Protein Binding; D017433:Protein Structure, Secondary; D019030:Receptors, Vitronectin / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000378:metabolism; D012471:Salivary Proteins and Peptides / Q000737:chemistry / Q000378:metabolism*; D012795:Sialoglycoproteins / Q000737:chemistry / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D009842:Oligopeptides; D010446:Peptide Fragments; D019030:Receptors, Vitronectin; D011993:Recombinant Fusion Proteins; C506895:SPP1 protein, human; C018149:STATH protein, human; D012471:Salivary Proteins and Peptides; D012795:Sialoglycoproteins; D053495:Osteopontin; C047981:arginyl-glycyl-aspartic acid; D017886:Durapatite