Biomolecular condensates formed via phase separation of intrinsically disordered proteins/regions (IDPs/IDRs) and nucleic acids are associated with cell physiology and disease. Water makes up for ∼60–70% of the condensate volume and is thought to influence the complex interplay of chain–chain and chain–solvent interactions, modulating the mesoscale properties of condensates. The behavior of water in condensates and the key roles of protein hydration water in driving the phase separation remain elusive. Here, we employ single-droplet vibrational Raman spectroscopy to illuminate the structural redistribution within protein hydration water during the phase separation of neuronal IDPs. Our Raman measurements reveal the changes in the water hydrogen bonding network during homotypic and heterotypic phase separation governed by various molecular drivers. Such single-droplet water Raman measurements offer a potent generic tool to unmask the intriguing interplay of sequence-encoded chain–chain and chain–solvent interactions governing macromolecular phase separation into membraneless organelles, synthetic condensates, and protocells.

中文翻译：

---

相分离生物分子缩合物中水的氢键网络


通过本质上无序的蛋白质/区域（IDP/IDR）和核酸的相分离形成的生物分子缩合物与细胞生理学和疾病相关。水占冷凝物体积的~60-70%，被认为影响链-链和链-溶剂相互作用的复杂相互作用，调节冷凝物的介观性质。冷凝物中水的行为以及蛋白质水合水在驱动相分离中的关键作用仍然难以捉摸。在这里，我们采用单滴振动拉曼光谱来阐明神经元 IDP 相分离过程中蛋白质水合水中的结构重新分布。我们的拉曼测量揭示了在各种分子驱动因素控制下的同型和异型相分离过程中水氢键网络的变化。这种单滴水拉曼测量提供了一种有效的通用工具，可以揭示序列编码的链-链和链-溶剂相互作用之间有趣的相互作用，这些相互作用控制着大分子相分离成无膜细胞器、合成凝聚物和原始细胞。