Computational Modeling of an Associative Polymer Complex: the Effects of Stoichiometry

Abstract

Research into liquid-liquid phase separation has become essential to cell biology in recent years. Numerous studies addressing the physical properties of membraneless organelles, their biological functions and the mechanisms of phase separation have deepened our understanding of this newly appreciated class of subcellular structures. In this project, we propose a mechanism by which cells can tune the physical properties of phase-separated biopolymer complexes. We developed a minimalistic computational model to show that the transport properties of an associative polymer complex are strongly dependent on relative stoichiometry of specific binding sites. Hence, by adjusting the relative abundance of binding sites, cells can change the physical properties of "droplets". The theoretical results presented here can provide insight into experimental studies addressing the aberrant maturation processes of intracellular liquid droplets underlying the pathology of several neurodegenerative diseases.