Surface tension measurement and calculation of model biomolecular condensates.
Surface tension measurement and calculation of model biomolecular condensates.
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作者：
富含蛋白质的类液体生物分子凝聚物的表面张力是一种新兴的物理原理，它控制着生物细胞的介观内部组织。在这项研究中，我们提出了一种方法来评估模型生物分子冷凝物的表面张力，通过直的毛细管长度和冷凝物密度的座滴测量。我们的方法绕过了需要表征凝析油粘度，这是需要在以前报道的技术。我们证明了这种方法使用模型的缩合物，包括两个突变体的内在无序的蛋白质Ddx 4 N。值得注意的是，我们发现了蛋白质净电荷增加对Ddx 4 N缩合物表面张力的不利影响。此外，我们探讨了Scheutjens-Fleer理论的应用，通过自洽的平均场框架，使用Flory-Huggins相互作用参数计算凝聚体表面张力。这个相对简单的理论提供了半定量的准确性预测Ddx 4 N冷凝物表面张力，并使冷凝物表面的分子组织的评价。我们的发现揭示了生物分子凝聚物中流体-流体界面的分子细节。提出了包括相分离的Ddx 4 N的模型生物分子凝聚物的表面张力的直接座滴测量。我们比较这些与理论计算的基础上，围绕自洽Scheutjens-Fleer理论。
The surface tension of liquid-like protein-rich biomolecular condensates is an emerging physical principle governing the mesoscopic interior organisation of biological cells. In this study, we present a method to evaluate the surface tension of model biomolecular condensates, through straighforward sessile drop measurements of capillary lengths and condensate densities. Our approach bypasses the need for characterizing condensate viscosities, which was required in previously reported techniques. We demonstrate this method using model condensates comprising two mutants of the intrinsically disordered protein Ddx4N. Notably, we uncover a detrimental impact of increased protein net charge on the surface tension of Ddx4N condensates. Furthermore, we explore the application of Scheutjens–Fleer theory, calculating condensate surface tensions through a self-consistent mean-field framework using Flory–Huggins interaction parameters. This relatively simple theory provides semi-quantitative accuracy in predicting Ddx4N condensate surface tensions and enables the evaluation of molecular organisation at condensate surfaces. Our findings shed light on the molecular details of fluid–fluid interfaces in biomolecular condensates. Straightforward sessile drop measurements of surface tension for model biomolecular condensates comprising phase-separated Ddx4N are presented. We compare these with theoretical calculations, based around the self-consistent Scheutjens–Fleer theory.
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DOI：
10.1073/pnas.1706197114
发表时间：
2017-09-26
影响因子：
11.1
作者：
Brady, Jacob P.;Farber, Patrick J.;Kay, Lewis E.
通讯作者：
Kay, Lewis E.
影响因子：
23.5
作者：
Dai, Yifan;Chamberlayne, Christian F.;Chilkoti, Ashutosh
通讯作者：
Chilkoti, Ashutosh
影响因子：
4.4
作者：
Aarts, DGAL;Dullens, RPA;van Roij, R
通讯作者：
van Roij, R
影响因子：
64.5
作者：
Feric M;Vaidya N;Harmon TS;Mitrea DM;Zhu L;Richardson TM;Kriwacki RW;Pappu RV;Brangwynne CP
通讯作者：
Brangwynne CP
影响因子：
64.5
作者：
Banani SF;Rice AM;Peeples WB;Lin Y;Jain S;Parker R;Rosen MK
通讯作者：
Rosen MK