Molecular-Dynamics Simulation of Rearrangements in the Conformational Structure of Polyampholytic Macromolecules on the Surface of a Polarized Metal Nanoparticle

Abstract

Molecular dynamics has been employed to study rearrangements in the conformational structure of polyampholytic macrochains with different distributions of charged units in the electric field of a polarized metal nanoparticle. The angular and radial distributions have been calculated for the average densities of polypeptide atoms. The radial distributions of the average density of polypeptide atoms have been obtained in the vicinities of the positively and negatively charged poles of the nanoparticle, as well as in its equatorial region. An analytical model has been proposed for conformational rearrangements of an adsorbed macrochain in the field of the polarized nanoparticle. The formation a nonuniform distribution of the density of polypeptide atoms has been analyzed as depending on the angle between the directions of the dipole moment vector and the vector of the normal to the nanoparticle surface. Swelling of the macromolecular “fringe” has been observed with the predominant protrusion of loops in the direction of the polarization axis.