Rearrangements in the Conformational Structure of Polypeptides on the Surface of a Metal Nanowire in Rotating Electric Field: Molecular Dynamics Simulation

Abstract

Molecular dynamics has been employed to study conformational rearrangements of polyampholytic and uniformly charged polypeptides adsorbed on the surface of a transversely polarized nanowire, in particular, upon rotation of the polarizing electric field vector. On the surface of the transversely polarized nanowire, a fringe consisting of polyampholitic polypeptide macromolecules is protruded in the direction of polarization, while uniformly charged polypeptide is shifted to the polarized regions of the cross section that are charged oppositely to the charge of macrochain units. The larger the distance between oppositely charged units in the polyampholytic polypeptide, the higher the ratio between the fringe thicknesses in the direction of polarization and in the orthogonal direction in the cross section plane. In an electric field rotating around the axis of the metal nanowire, uniformly charged polypeptides adsorbed on its surface rotate around the wire in the same direction. The same phenomenon has been observed for polyampholytic polypeptides, in which the distances between negatively and positively charged units in macrochains are longer than the half-circumference of the nanowire.