Emergence of Secondary Motifs in Tube-Like Polymers in a Solvent

TL;DR

This paper investigates how specific entropic and solvophobic interactions induce secondary motif formation in tube-like polymers within a solvent, combining analytical and simulation approaches to understand their conformational preferences.

Contribution

It introduces a combined analytical and numerical study of how entropic and solvophobic interactions lead to secondary motif emergence in polymers, considering finite length and discretization effects.

Findings

Secondary motifs form due to entropic and solvophobic interactions.

Finite polymer length influences preferred conformations.

Discrete versus continuum models affect system behavior.

Abstract

We study the effects of two kinds of interactions in tube-like polymers and demonstrate that they result in the formation of secondary motifs. The first has an entropic origin and is a measure of the effective space available to the solvent. The second arises from solvophobic interactions of the solvent with the polymers and leads to an energy proportional to the contact surface between the tube and solvent particles. The solvent molecules are modeled as hard spheres and the two interactions are considered separately with the solvent density affecting their relative strength. In addition to analytical calculations, we present the results of numerical simulations in order to understand the role played by the finite length of short polymers and the discrete versus continuum descriptions of the system in determining the preferred conformation.