Phase Transitions in Biological Systems with Many Components
Phase Transitions in Biological Systems with Many Components
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DOI：
10.1016/j.bpj.2016.10.043
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发表时间：
2017-02-28
影响因子：
3.4
通讯作者：
Frenkel, Daan
中科院分区：
文献类型：
--
作者：
Jacobs, William M.;Frenkel, Daan
生物混合物（例如细胞质）可能由数千种不同的成分组成。现在有大量证据表明，在生理条件下，细胞内混合物可以相分离成具有不同组成的空间上不同的区域。在本文中，我们提供了数字证据，表明这种自发区室化利用了多组分生物分子混合物相图的一般特征。特别是，我们表明，当分子间相互作用强度的方差超过明确定义的阈值时，分层域可能会分离。在非常相似的条件下，多个不同的相可能会变得稳定，然后可以对其进行调整以实现多相共存。因此，只需要对细胞质的组成或分子间相互作用的强度进行微小的调整来调节具有特定组成的不同域的形成，这意味着相分离是创建空间组织的稳健机制。我们进一步预测，系统中组件数量的增加只会对该功能产生微弱的影响。因此，我们的模型表明，出于纯粹的物理化学原因，生物混合物自然会经历少量的分层相变。
Biological mixtures such as the cytosol may consist of thousands of distinct components. There is now a substantial body of evidence showing that, under physiological conditions, intracellular mixtures can phase separate into spatially distinct regions with differing compositions. In this article we present numerical evidence indicating that such spontaneous compartmentalization exploits general features of the phase diagram of a multicomponent biomolecular mixture. In particular,we show that demixed domains are likely to segregate when the variance in the intermolecular interaction strengths exceeds a well-defined threshold. Multiple distinct phases are likely to become stable under very similar conditions, which can then be tuned to achieve multiphase coexistence. As a result, only minor adjustments to the composition of the cytosol or the strengths of the intermolecular interactions are needed to regulate the formation of different domains with specific compositions, implying that phase separation is a robust mechanism for creating spatial organization. We further predict that this functionality is only weakly affected by increasing the number of components in the system. Our model therefore suggests that, for purely physico-chemical reasons, biological mixtures are naturally poised to undergo a small number of demixing phase transitions.