Designing Electrostatic Interactions via Polyelectrolyte Monomer Sequence
Designing Electrostatic Interactions via Polyelectrolyte Monomer Sequence
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DOI：
10.1021/acscentsci.9b00087
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发表时间：
2019-04-24
影响因子：
18.2
通讯作者：
Sing, Charles E.
中科院分区：
文献类型：
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作者：
Lytle, Tyler K.;Chang, Li-Wei;Sing, Charles E.
带电聚合物在生物系统中无处不在，因为静电相互作用可以驱动复杂的结构形成，并响应环境参数，如离子强度和ph。在这些系统中，功能来自复杂的分子设计；例如，内在无序的蛋白质利用特定的单体电荷序列来控制被称为无膜细胞器的细胞内区室的形成和功能。带电单体序列在决定静电相互作用强度方面的作用仍然知之甚少，尽管有大量证据表明，序列是生物学用来调节软材料的强大工具。在这篇文章中，我们使用理论、实验和模拟的结合来建立控制静电相互作用的顺序驱动控制的物理原理。我们预测了任意电荷序列如何引起静电相互作用和相应相行为的剧烈变化。我们推广了一种描述相分离现象的传递矩阵形式，称为“复凝聚”，并提供了一个理论框架来预测电荷序列的相行为。因此，这项工作为如何在生物学中使用电荷序列以及如何将其用于合成聚合物系统的工程特性提供了见解。
Charged polymers are ubiquitous in biological systems because electrostatic interactions can drive complicated structure formation and respond to environmental parameters such as ionic strength and pH. In these systems, function emerges from sophisticated molecular design; for example, intrinsically disordered proteins leverage specific sequences of monomeric charges to control the formation and function of intracellular compartments known as membraneless organelles. The role of a charged monomer sequence in dictating the strength of electrostatic interactions remains poorly understood despite extensive evidence that sequence is a powerful tool biology uses to tune soft materials. In this article, we use a combination of theory, experiment, and simulation to establish the physical principles governing sequence-driven control of electrostatic interactions. We predict how arbitrary sequences of charge give rise to drastic changes in electrostatic interactions and correspondingly phase behavior. We generalize a transfer matrix formalism that describes a phase separation phenomenon known as "complex coacervation" and provide a theoretical framework to predict the phase behavior of charge sequences. This work thus provides insights into both how charge sequence is used in biology and how it could be used to engineer properties of synthetic polymer systems.