Smokers Iris B A, Spruijt Evan
Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6523 AJ Nijmegen, The Netherlands.
Biomacromolecules. 2025 Jan 13;26(1):363-373. doi: 10.1021/acs.biomac.4c01201. Epub 2024 Dec 2.
Accurate determination of biomolecular condensate volume reveals that destabilization of condensates can lead to either swelling or shrinking of condensates, giving fundamental insights into the regulation of the volume of cellular condensates. Determination of the volume of biomolecular condensates and coacervate protocells is essential to investigate their precise composition and impact on (bio)chemical reactions that are localized inside the condensates. It is not a straightforward task, as condensates have tiny volumes, are highly viscous, and are prone to wetting. Here, we examine different strategies to determine condensate volume and introduce two new methods, with which condensate volumes of 1 μL or less (volume fraction 0.4%) can be determined with a standard deviation of 0.03 μL. Using these methods, we show that the swelling or shrinking of condensates depends on the degree of physical cross-linking. These observations are supported by Flory-Huggins theory and can have profound effects on condensates in cell biology.
对生物分子凝聚物体积的准确测定表明，凝聚物的不稳定会导致凝聚物体积膨胀或收缩，这为细胞凝聚物体积的调节提供了基本见解。测定生物分子凝聚物和凝聚相原细胞的体积对于研究它们的精确组成以及对凝聚物内部局部（生物）化学反应的影响至关重要。这并非一项简单的任务，因为凝聚物体积微小、粘性极高且容易被润湿。在这里，我们研究了测定凝聚物体积的不同策略，并引入了两种新方法，利用这两种方法可以测定体积为1 μL或更小（体积分数0.4%）的凝聚物，标准偏差为0.03 μL。使用这些方法，我们表明凝聚物的膨胀或收缩取决于物理交联程度。这些观察结果得到了弗洛里 - 哈金斯理论的支持，并且可能对细胞生物学中的凝聚物产生深远影响。
