标题： 溶剂混合物中聚合物之间的异常长程硬墙排斥及其对生物分子凝聚物的含义 显示英文标题

标题： Anomalous Long-range Hard-wall Repulsion between Polymers in Solvent Mixtures and Its Implication for Biomolecular Condensates

摘要： 在溶剂混合物中的聚合物系统是一个广泛使用的模型，用于表示细胞内环境中的生物分子凝聚物。 在这里，我们应用一种变分理论来控制两个聚合物的质心，并对它们在溶剂混合物中的相互作用进行了首次量化。 即使溶剂和共溶剂都对聚合物有利，我们证明了强聚合物-共溶剂亲和力会诱导形成单链凝聚物。 尽管所有的分子相互作用都是软的，两个凝聚物之间的平均力势表现出一种长程硬墙排斥的异常特征，这种特征无法归类为任何现有的链间相互作用类型。 这种排斥随着亲和力或体相共溶剂分数的增加而增强。 其潜在机制是共溶剂调节，表现为共溶剂的不连续局部凝聚。 硬墙排斥提供了一种动力学屏障，以防止凝聚物的融合，从而突显了蛋白质作为共溶剂在稳定生物分子凝聚物中的内在作用。 显示英文摘要

摘要： The system of polymers in solvent mixtures is a widely-used model to represent biomolecular condensates in intracellular environments. Here, we apply a variational theory to control the center-of-mass of two polymers and perform the first quantification of their interactions in solvent mixtures. Even both solvent and cosolvent are good to the polymer, we demonstrate that strong polymer-cosolvent affinity induces the formation of a single-chain condensate. Even though all the molecular interactions are soft, the potential of mean force between two condensates exhibits an anomalous feature of long-range hard-wall repulsion, which cannot be categorized into any existing types of inter-chain interactions. This repulsion is enhanced as either the affinity or the bulk cosolvent fraction increases. The underlying mechanism is cosolvent regulation manifested as a discontinuous local condensation of cosolvent. The hard-wall repulsion provides a kinetic barrier to prevent coalescence of condensates and hence highlights the intrinsic role of proteins as a cosolvent in stabilizing biomolecular condensates.