Sequence Effects on Internal Structure of Droplets of Associative Polymers

TL;DR

This study uses Langevin dynamics simulations to explore how the sequence of associative polymers influences their internal organization within droplets, revealing shape and clustering variations.

Contribution

It demonstrates the impact of polymer sequence on droplet internal structure and aging phenomena, providing insights into protein condensate behavior.

Findings

Shape and cluster organization depend on sticker placement.

Aging occurs in telechelic polymers but not in other sequences.

Sequence variation alters droplet morphology and dynamics.

Abstract

We used Langevin dynamics simulations of short associative polymers with two stickers placed symmetrically along their contour to study the effect of the primary sequence of these polymers on their organization inside condensed droplets. We observed that the shape, size and number of sticker clusters inside the condensed droplet change from a single cylindrical fiber to many compact clusters, as one varies the location of stickers along the chain contour. Aging due to conversion of intramoleclular to intermolecular associations was observed in droplets of telechelic polymers, but not for other sequences of associating polymers. The relevance of our results to condensates of intrinsically disordered proteins is discussed.