Rotational dynamics of proteins in nanochannels: role of solvent’s local viscosity

Abstract

Viscosity variation of solvent in local regions near a solid surface, be it a biological surface of a protein or an engineered surface of a nanoconfinement, is a direct consequence of intermolecular interactions between the solid body and the solvent. The current coarse-grained molecular dynamics study takes advantage of this phenomenon to investigate the anomaly in a solvated protein’s rotational dynamics confined using a representative solid matrix. The concept of persistence time, the characteristic time of structural reordering in liquids, is used to compute the solvent’s local viscosity. With an increase in the degree of confinement, the confining matrix significantly influences the solvent molecule’s local viscosity present in the protein hydration layer through intermolecular interactions. This effect contributes to the enhanced drag force on protein motion, causing a reduction in the rotational diffusion coefficient. Simulation results suggest that the direct matrix-protein non-bonded interaction is responsible for the occasional jump and discontinuity in orientational motion when the protein is in very tight confinement.

Bio-inspired adhesion control with liquids

“…During the locomotion of insects, secretions must be supplied to the tips of the adhesive elements to keep wet adhesion in a normal operation state. Thus, it is necessary to explore the delivery of adhesive liquids through nanochannels to the surface (Andersson et al, 2017;Haridasan and Sathian 2021;Nazari et al, 2020;Wang et al, 2018b;Zhang et al, 2019a). Up to now, a few papers have reported the ll OPEN ACCESS transport of secretions in insects.…”