Conformational Properties of Polymers at Droplet Interfaces as Model Systems for Disordered Proteins

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Jiahui Wang - , Texas A&M University (Author)
  • Dinesh Sundaravadivelu Devarajan - , Texas A&M University (Author)
  • Arash Nikoubashman - , Chair of Theory of Bioinspired Polymers, Johannes Gutenberg University Mainz, Leibniz Institute of Polymer Research Dresden (Author)
  • Jeetain Mittal - , Texas A&M University (Author)

Abstract

Polymer models serve as useful tools for studying the formation and physical properties of biomolecular condensates. In recent years, the interface dividing the dense and dilute phases of condensates has been discovered to be closely related to their functionality, but the conformational preferences of the constituent proteins remain unclear. To elucidate this, we perform molecular simulations of a droplet formed by phase separation of homopolymers as a surrogate model for the prion-like low-complexity domains. By systematically analyzing the polymer conformations at different locations in the droplet, we find that the chains become compact at the droplet interface compared with the droplet interior. Further, segmental analysis revealed that the end sections of the chains are enriched at the interface to maximize conformational entropy and are more expanded than the middle sections of the chains. We find that the majority of chain segments lie tangential to the droplet surface, and only the chain ends tend to align perpendicular to the interface. These trends also hold for the natural proteins FUS LC and LAF-1 RGG, which exhibit more compact chain conformations at the interface compared to the droplet interior. Our findings provide important insights into the interfacial properties of biomolecular condensates and highlight the value of using simple polymer physics models to understand the underlying mechanisms.

Details

Original languageEnglish
Pages (from-to)1472-1478
Number of pages7
JournalACS macro letters
Volume12
Issue number11
Publication statusPublished - 21 Nov 2023
Peer-reviewedYes

External IDs

PubMed 37856873