Decoding the physical principles of two-component biomolecular phase separation.
Decoding the physical principles of two-component biomolecular phase separation.
复制标题
解读双组份生物分子相分离的物理原理。
DOI：
10.7554/elife.62403
复制
发表时间：
2021-03-11
期刊：
影响因子：
7.7
通讯作者：
Wingreen NS
中科院分区：
文献类型：
--
作者：
Zhang Y;Xu B;Weiner BG;Meir Y;Wingreen NS
细胞具有许多非膜结合的隔室，这些隔室通过液-液相分离而形成。这些凝聚体根据需要组装和溶解，以实现中央细胞功能。一类重要的凝析油是由形成一对一特定键的两个缔合聚合物物种组成的凝析油。在这样的系统中，构成相分离的物理原理是什么？为了解决这个问题，我们使用了粗粒度的分子动力学模拟来检查相边界如何依赖于聚合物的价态、化学计量比和结合强度。我们发现了一个显著的现象--对于足够强的结合，相分离在合理的聚合物化学计量比下被抑制，我们称之为魔术比效应。我们进一步发展了分析二聚体-凝胶理论，证实了魔术比效应，并解开了聚合物性质在相图形成中的单独作用。我们的工作为控制生物分子凝聚物相图的因素提供了新的见解，并对自然和合成系统产生了影响。
Cells possess a multiplicity of non-membrane-bound compartments, which form via liquid-liquid phase separation. These condensates assemble and dissolve as needed to enable central cellular functions. One important class of condensates is those composed of two associating polymer species that form one-to-one specific bonds. What are the physical principles that underlie phase separation in such systems? To address this question, we employed coarse-grained molecular dynamics simulations to examine how the phase boundaries depend on polymer valence, stoichiometry, and binding strength. We discovered a striking phenomenon – for sufficiently strong binding, phase separation is suppressed at rational polymer stoichiometries, which we termed the magic-ratio effect. We further developed an analytical dimer-gel theory that confirmed the magic-ratio effect and disentangled the individual roles of polymer properties in shaping the phase diagram. Our work provides new insights into the factors controlling the phase diagrams of biomolecular condensates, with implications for natural and synthetic systems.