The effect of monomer polarizability on the stability and salt partitioning in model coacervates
The effect of monomer polarizability on the stability and salt partitioning in model coacervates
复制标题
单体极化率对模型凝聚层稳定性和盐分配的影响
DOI：
10.1039/d3sm00706e
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发表时间：
2023
期刊：
影响因子：
3.4
通讯作者：
Riggleman, Robert Andrew
中科院分区：
文献类型：
--
作者：
Jedlinska, Zuzanna Maria;Riggleman, Robert Andrew
带电聚合物链的凝聚一直是聚合物科学和生物科学中的一个主要研究课题，因为它是一种称为液-液相分离(LLP)现象的子集。在这一过程中，富聚合物相从贫聚上清液中分离出来，同时仍保持其类似液体的性质。LLP通过驱动无膜细胞器的形成，在细胞内稳态中起着至关重要的作用。它还有可能被利用来帮助进行新的治疗应用。最近的研究表明，驱动LLP的机制并不简单，而是静电、偶极、疏水和其他弱相互作用共同作用的结果。使用粗粒聚合物模拟，我们研究了相对未知的单体极化率和空间变化的介电常数对LLP倾向的影响，以及这些因素对所产生的凝析油的性质的影响。为了产生介电常数的空间变化，我们所有的模拟都包括了显式的溶剂和反离子。我们证明了极化率对凝聚体行为的影响很小，但当考虑到离子分配和微观结构时，极化率起着重要作用。我们观察到，主要的贡献来自于中性嵌段的性质，因为赋予它们一个诱导偶极子会使它们的性质从疏水变为亲水。我们假设，这项工作的结果可以通过提供一个总体框架并通过突出影响有限责任合伙的重要因素来帮助指导未来与有限责任合伙有关的研究。
Coacervation of charged polymer chains has been a topic of major interest in both polymer and biological sciences, as it is a subset of a phenomenon called liquid–liquid phase separation (LLPS). In this process the polymer-rich phase separates from the polymer-lean supernatant while still maintaining its liquid-like properties. LLPS has been shown to play a crucial role in cellular homeostasis by driving the formation of membraneless organelles. It also has the potential to be harnessed to aid in novel therapeutical applications. Recent studies have demonstrated that there is no one simple mechanism which drives LLPS, which is instead a result of the combined effect of electrostatic, dipolar, hydrophobic, and other weak interactions. Using coarse-grained polymer simulations we investigate the relatively unexplored effects of monomer polarizability and spatially varying dielectric constant on LLPS propensity, and these factors affect the properties of the resulting condensates. In order to produce spatial variations in the dielectric constant, all our simulations include explicit solvent and counterions. We demonstrate that polarizability has only a minor effect on the bulk behaviour of the condensates but plays a major role when ion partitioning and microstructure are considered. We observe that the major contribution comes from the nature of the neutral blocks as endowing them with an induced dipole changes their character from hydrophobic to hydrophilic. We hypothesize that the results of this work can aid in guiding future studies concerned with LLPS by providing a general framework and by highlighting important factors which influence LLPS.