Leurs Yannick H A, Giezen Sanne N, Li Yudong, van den Hout Willem, Beeren Jay, van den Aker Linn J M, Voets Ilja K, van Hest Jan C M, Brunsveld Luc
Laboratory of Chemical Biology, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, 5612 AZ, The Netherlands.
Bio-Organic Chemistry, Departments of Biomedical Engineering and of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven, 5612 AZ, The Netherlands.
J Am Chem Soc. 2025 Jun 4;147(22):18412-18418. doi: 10.1021/jacs.5c03740. Epub 2025 May 24.
Coacervates have been widely used to mimic membraneless organelles (MLOs). However, coacervates without a membrane or stabilizing surface do not feature the same level of stability as MLOs. This study shows that specifically engineered surface-active proteins can interact with the interface of polypeptide coacervates, conferring resistance to coacervate dissolution and fusion. Modulating the molecular characteristics of these coacervate stabilizing proteins highlighted that their dimerization aids in achieving effective interface stabilizers. Cryo-TEM imaging showed a densely packed protein monolayer at the coacervate-liquid interface, while single-molecule super-resolution microscopy captured the dynamic nature of this protein layer, with the proteins rapidly (un)docking and moving across the coacervate interface within milliseconds. These findings suggest a dynamic form of coacervate stabilization driven by transient protein interactions at the condensate interface. This unique form of coacervate stabilization not only provides a new approach to developing stable and dynamically exchanging synthetic condensate systems but, as model systems, can also significantly contribute to our understanding of the mechanisms underlying the temporal stability of MLOs in nature.
凝聚物已被广泛用于模拟无膜细胞器（MLOs）。然而，没有膜或稳定表面的凝聚物并不具备与MLOs相同水平的稳定性。这项研究表明，经过特殊工程设计的表面活性蛋白可以与多肽凝聚物的界面相互作用，赋予凝聚物抗溶解和抗融合的能力。对这些凝聚物稳定蛋白的分子特性进行调控突出表明，它们的二聚化有助于实现有效的界面稳定剂。冷冻透射电子显微镜成像显示在凝聚物 - 液体界面处有密集堆积的蛋白质单层，而单分子超分辨率显微镜捕捉到了该蛋白质层的动态性质，蛋白质在几毫秒内快速（解）对接并在凝聚物界面上移动。这些发现表明，凝聚物的稳定是由凝聚物界面处的瞬时蛋白质相互作用驱动的一种动态形式。这种独特的凝聚物稳定形式不仅为开发稳定且能动态交换的合成凝聚系统提供了一种新方法，而且作为模型系统，还能极大地有助于我们理解自然界中MLOs时间稳定性的潜在机制。
