Adsorption of RGD Tripeptide on Au (111) Surface

Abstract

To date, many studies have been performed on interactions between amino acids and inorganic surfaces. However, the interactions are still in debate. Au is one of important biometals with inertness and subsequent biocompatibility in a living body. Because amino acids tend to adsorb on Au surface, it is required to investigate interactions between amino acids and Au surface for safe application of Au. In the present work, adsorption of RGD (arginine-glycine-aspartic acid, Arg-Gly-Asp) sequence on Au (111) surface is investigated by first principles calculations. When two oxygen atoms of carboxyl group in Asp were located very close to the atop sites of the Au surface, RGD was the most stable on the Au surface, like the adsorption of a single molecule of Asp on the Au surface. The adsorption energy of RGD on the Au surface was lower than that of Asp on the Au surface. This is because the negative hyperpolarization of Asp side chain and the positive hyperpolarization of Arg side chain are enhanced by the RGD sequence.