Rigidity enhances a magic-number effect in polymer phase separation
Rigidity enhances a magic-number effect in polymer phase separation
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DOI：
10.1038/s41467-020-15395-6
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发表时间：
2020-03-25
影响因子：
16.6
通讯作者：
Wingreen, Ned S.
中科院分区：
文献类型：
--
作者：
Xu, Bin;He, Guanhua;Wingreen, Ned S.
细胞拥有非膜结合体，其中许多现在被理解为相分离的凝聚体。一类此类缩合物由两种聚合物组成，其中每种聚合物均由重复的结合位点组成，这些结合位点以一对一的方式与另一种聚合物的结合位点相互作用。生物驱动模型表明，如果两种聚合物能够形成完全键合的小寡聚物，因为一种聚合物中的结合位点数量是另一种聚合物中结合位点数量的整数倍，则“幻数效应”会抑制相分离。在这里，我们使用晶格模型模拟和分析计算来表明，如果其中一种聚合物具有允许多种不同键合构象的刚性形状，则可以大大增强这种魔数效应。此外，如果一种物质是刚性的，则在两种物质的相对浓度范围更大的范围内，该效应是稳健的。对于结合位点数量的某些组合，魔数效应可以抑制两种缔合聚合物的相分离。在这里，作者使用晶格模拟和分析计算来表明，如果一个组件具有刚性形状，则可以大大增强这种魔数效应。
Cells possess non-membrane-bound bodies, many of which are now understood as phase-separated condensates. One class of such condensates is composed of two polymer species, where each consists of repeated binding sites that interact in a one-to-one fashion with the binding sites of the other polymer. Biologically-motivated modeling revealed that phase separation is suppressed by a "magic-number effect" which occurs if the two polymers can form fully-bonded small oligomers by virtue of the number of binding sites in one polymer being an integer multiple of the number of binding sites of the other. Here we use lattice-model simulations and analytical calculations to show that this magic-number effect can be greatly enhanced if one of the polymer species has a rigid shape that allows for multiple distinct bonding conformations. Moreover, if one species is rigid, the effect is robust over a much greater range of relative concentrations of the two species. The phase separation of two species of associating polymers is suppressed by a magic-number effect for certain combinations of the numbers of binding sites. Here the authors use lattice simulations and analytical calculations to show that this magic-number effect can be greatly enhanced if one component has a rigid shape.