The interaction between proteins and the surfaces of inorganic materials is of great importance in natural systems and a long studied topic. What is yet to be fully understood is the mechanism that determines such interactions, in particular, for a given surface, which aminoacid, if any, binds and, in that case, what is the nature of the binding. The Au(111) surface, due to its utilization in several bioelectronics and biological applications, is one of the most commonly used substrates for experimental investigations. Among others, various experimental results have shown a clear affinity between the natural aminoacid histidine and the gold surface. Because the main contribution to the protein-surface interaction is likely mediated by the solvent accessible sidechains, we have focused our attention on imidazole, the molecule representing histidine side chain. Plane waves DFT calculations, in the supercell approach, have been performed to evaluate the nature of the interaction. Our results indicate the presence of a 'on top' adsorption geometry with a covalent contribution to the binding between the unprotonated nitrogen atom and the superficial gold atom directly below it.
Unraveling the interaction between histidine side chain and the Au(111) surface: A DFT study
Corni S;Di Felice R
2008
Abstract
The interaction between proteins and the surfaces of inorganic materials is of great importance in natural systems and a long studied topic. What is yet to be fully understood is the mechanism that determines such interactions, in particular, for a given surface, which aminoacid, if any, binds and, in that case, what is the nature of the binding. The Au(111) surface, due to its utilization in several bioelectronics and biological applications, is one of the most commonly used substrates for experimental investigations. Among others, various experimental results have shown a clear affinity between the natural aminoacid histidine and the gold surface. Because the main contribution to the protein-surface interaction is likely mediated by the solvent accessible sidechains, we have focused our attention on imidazole, the molecule representing histidine side chain. Plane waves DFT calculations, in the supercell approach, have been performed to evaluate the nature of the interaction. Our results indicate the presence of a 'on top' adsorption geometry with a covalent contribution to the binding between the unprotonated nitrogen atom and the superficial gold atom directly below it.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
