Synthesis and cell attachment activity of bioactive oligopeptides: RGD, RGDS, RGDV, and RGDT.

Tetrapeptides, Arg-Gly-Asp-Ser (RGDS), Arg-Gly-Asp-Val (RGDV), and Arg-Gly-Asp-Thr (RGDT), present in the cell-attachment domain of fibronectin, vitronectin, and collagen, respectively, were synthesized by using an improved liquid-phase procedure. Bioactivities of RGD and RGDX (X = S, V, and T) as cell recognition determinants were investigated by two methods to evaluate interactions of these oligopeptides with L-929 fibroblast cells originating in mouse epithelia. In the first method, these oligopeptides were immobilized to ethylene-acrylic acid copolymer (EAA) film, and the cell-attachment activity of the immobilized film was measured. In the second method, interaction of oligopeptides with the cells was evaluated by measuring the cell inhibition caused by oligopeptides. It was found that RGD and RGDX exhibit remarkable cell-attachment activity, and the activity of oligopeptides depends on X.