The aqueous conformation of cyclo(1,6)Ac‐Cys‐Arg‐Gly‐Asp‐Phe‐Pen‐NH₂

RGD peptides are known as important ligands for integrin receptors in the cell adhesion process. The selectivity of RGD peptides for a certain integrin receptor is partly dependent on the RGD conformation and the residues surrounding the RGD sequence. This paper investigates the effect of the addition of a phenylalanine residue on the RGD conformation in cyclo(1,6)Ac-Cys-Arg-Gly-Asp-Phe-Pen-NH2 (1) as compared to the previously studied cyclo(1,5)Ac-Pen-Arg-Gly-Asp-Cys-NH2 (2). The conformational study of peptide 1 was done in aqueous solution using nuclear magnetic resonance (NMR) spectroscopy and molecular dynamics simulations. This work will increase the understanding of the flanking residue's effect in RGD peptides.