Conformations, Dynamics, and Looping Kinetics of Partially Active Polymers

TL;DR

This paper analyzes how localized activity within a polymer chain affects its conformational, dynamical, and looping behaviors, revealing complex scaling and swelling patterns through analytical and simulation methods.

Contribution

It introduces a model for partially active polymers with localized activity, exploring how activity location and size influence their properties and dynamics.

Findings

Active segments cause polymer swelling and alter conformational properties.

Local activity significantly impacts mean squared displacement and looping times.

Anomalous scaling behaviors are observed in reconfiguration dynamics for intermediate chain lengths.

Abstract

We investigate the conformational and dynamical properties of a partially active Rouse chain, where activity is localized within a specific segment, positioned at various locations along the chain and spanning any given length. Through analytical methods and simulations, we reveal how the location and size of the active segment influence polymer swelling patterns. Likewise, we observe that the mean squared distance between two points along the polymer, as well as the mean squared displacement of a tagged point, are notably affected by the local activity. In addition, the reconfiguration and looping dynamics show anomalous scaling behaviors, particularly in intermediate chain lengths, capturing the interplay between persistence of active motion and polymer relaxation dynamics. Our model, relevant to spatially varying activity observed in active biopolymeric systems, provides a basis for exploring more realistic models of chromatin behavior, especially those incorporating heterogeneous activity.