Rearrangements in the conformational structure of polyampholytic polypeptides on the surface of a uniformly charged and polarized nanowire: Molecular dynamics simulation

Abstract

Molecular dynamics has been employed to study electrically induced rearrangements in the conformational structure of polyampholytic polypeptides adsorbed on the surface of a gold nanowire with a uniform distribution of electric charges and on the surface of a transversely polarized nanowire. The angular and radial distributions have been calculated for the average densities of polypeptide atoms. On the uniformly charged surface of the nanowire, the macromolecular "fringe" consisted of three layers: two differently charged layers and a neutral layer that was located between them. On the surface of a transversely polarized nanowire, swelling of the macromolecular “fringe” has been observed in the direction of polarization. The thickness of the polyampholytic "fringe" on a uniformly charged nanowire and the ratio of the thickness of the "fringe" in the direction of polarization to the thickness in the orthogonal direction in the cross section turned out to be the greater, the greater the distance between the oppositely charged units in the polyampholyte.