Molecular recognition by van der Waals interaction between polymers with sequence-specific polarizabilities

TL;DR

This paper investigates how sequence-specific anisotropic polarizabilities influence van der Waals interactions between polymers, revealing unique scaling laws and angular dependencies that could facilitate molecular recognition.

Contribution

It introduces a model for van der Waals interactions between polymers with sequence-specific polarizabilities, highlighting a novel $r^{-5}$ scaling for identical polymers and their angular attraction preferences.

Findings

Identical polymers exhibit a $r^{-5}$ van der Waals scaling at small separations.

Distinct polymers follow a $r^{-4}$ scaling behavior.

Aligned identical polymers experience enhanced attraction due to angular dependence.

Abstract

We analyze van der Waals interactions between two rigid polymers with sequence-specific, anisotropic polarizabilities along the polymer backbones, so that the dipole moments fluctuate parallel to the polymer backbones. Assuming that each polymer has a quenched-in polarizability sequence which reflects, for example, the polynucleotide sequence of a double-stranded DNA molecule, we study the van der Waals interaction energy between a pair of such polymers with rod-like structure for the cases where their respective polarizability sequences are (i) distinct and (ii) identical, with both zero and non-zero correlation length of the polarizability correlator along the polymer backbones in the latter case. For identical polymers, we find a novel $r^{-5}$ scaling behavior of the van der Waals interaction energy for small inter-polymer separation $r$, in contradistinction to the $r^{-4}$ scaling behavior of distinct polymers, with furthermore a pronounced angular dependence favoring attraction between sufficiently aligned identical polymers. Such behavior can assist the molecular recognition between polymers.