Conformations of polyglutamate chains near single walled carbon nanotubes.

Carbon nanotubes possess multi-functional characteristics due to their unique physiochemical properties. All atom, explicit-solvent molecular dynamics simulations is used to explore the conformations of the polyglutamate chains of different lengths and its surface interactions with single walled carbon nanotubes of different diameters. The adsorption of the polyglutamate chains on the surface of these carbon nanotubes is governed by two critical ratios that depends on the geometric parameters of the polyglutamate chains and the carbon nanotubes. The α-helical content of the polyglutamate chains decreases with the increase in diameter of the carbon nanotubes. The number of intramolecular hydrogen bonds in the polyglutamate chains decrease upon adsorption on the surface of the nanotubes as compared to those in its absence. Polyglutamate adsorption on carbon nanotubes is largely due to van der Waals interactions. Shorter polyglutamate chains are more prone to adsorption. The distribution of water molecules for the adsorbed polyglutamate chains show that adsorption is governed by hydrophilic interactions.