Gly-Arg-Gly-Asp-Ser-Pro-Lys is a RGD peptide. Naturally occurring RGD peptides, present in the ECM (extracellalar matrix) proteins, are involved in facilitating integrin-mediated cell adhesion to matrix proteins. RGD peptide is present as repeats in cell-adhesion protein, such as fibronectin and vitronectin. This tripeptide is recognized by cells by specific integrins (e.g. β1 , β3 , and β5 subunits), present on the cell surface and associated with the actin filament via the FA (focal adhesion)-complex.
