RGDS tetrapeptide binds to osteoblasts and inhibits fibronectin-mediated adhesion.
The mechanisms of osteoblast attachment to surfaces were probed using the adhesive tetrapeptide RGDS (Arg-Gly-Asp-Ser) and the related but non-adhesive RGES (Arg-Gly-Glu-Ser). Specifically, RGDS and RGES were investigated for their ability both to bind to a suspension of well-characterized neonatal rat calvarial osteoblasts and to inhibit cell attachment to fibronectin-coated microtiter plates. RGDS bound to the cells with an average Kd approximately 9.4 x 10(-4) M, and RGES bound with an average Kd approximately 3.0 x 10(-4) M; at saturation, the osteoblasts bound almost twice as much RGDS as RGES. RGDS partially inhibited cell adhesion (55% to 60%) in a competitive, dose-dependent manner. In contrast, RGES had minimal effect on cell attachment. Since complete inhibition of attachment was not observed, it is likely that a synergistic adhesion site in the fibronectin molecule and/or cell surface molecules such as proteoglycans are active in mediating osteoblast/substrate adhesion.
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Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180-3590.
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D000595:Amino Acid Sequence; D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D002478:Cells, Cultured; D005353:Fibronectins / Q000037:antagonists & inhibitors*; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism*; D010006:Osteoblasts / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D016024:Receptors, Cytoadhesin / Q000378:metabolism
D005353:Fibronectins; D009842:Oligopeptides; D016024:Receptors, Cytoadhesin; C059453:RGES peptide; C046617:arginyl-glycyl-aspartyl-serine