Adsorption of histidine and histidine-containing peptides on Au(1 1 1): A molecular dynamics study

The adsorption behavior of histidine (His) and three His-derived peptides, glycyl-histidine (Gly-His), glycyl-histidine-glycine (Gly-His-Gly), and glycyl-glycyl-histidine (Gly-Gly-His) on the Au(1 1 1) surface has been studied using molecular dynamics simulations. All the four kinds of amino acids adsorbed from the liquid phase onto the Au(1 1 1) surface after a 3 ns MD run, as expected. Many statistical properties of His and His-derived peptides, like the interaction energy of adsorption, were analyzed after the systems reaching equilibrium. We have proven that His and His-derived peptides adsorbed on Au(1 1 1) via the imino nitrogen in the imidazole (IM) ring and the carboxylic acid group at the molecular level. Au(1 1 1) surface first adsorb the dipeptide Gly-His among the four amino acids and the sequence of residues in a peptide can significantly influence adsorption geometry of amino acids rather than the adsorption rate. Our work agrees well with available experimental data and shows a clear insight into the interaction between His-containing amino acids and Au(1 1 1) surface at a microscopic level, which is helpful to future rational design efforts of gold-binding polypeptides.