The Effect of Side-Chain Polarity and Solvation Layers on the Interaction of Amino Acids with ZnS Surface: Adsorption Free Energies from Molecular Dynamics Simulations

Interaction of proteins with inorganic surfaces are of high importance in biological eventsand biotechnological applications [1-3]. However, the underlying interactions are still not wellunderstood. Here, the adsorption of different amino acids as protein building blocks onto a ZnS(110) is investigated. In this study, Molecular dynamics simulations (MD) combined withumbrella sampling technique are carried out to determine potentials of mean force (PMF) foramino acids in aqueous environment near the surface. According to the adsorption profiles of thestrongest binding side chains, two regions can be identified. The density profile of water nearsurface shows undulations which are symmetrical to the pattern of maxima and minima in energyprofiles. Depending on the size and polarity of the side chain, amino acid can adsorb to the firstor second solvation layer. These observations reveal the strong dependence of adsorption energyand binding conformation on the chemical character of amino acid and its side chain. Thesimulations also emphasize the key role of solvation layer in adsorption of biomolecules atinorganic surfaces.

کلیدواژه ها:

Potential of Mean Force ، Inorganic Surface ، Solvation Layer ، Adsorption Energy ، Umbrella Sampling ، Molecular Dynamics Simulation