Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85748, Garching, Germany.
Angew Chem Int Ed Engl. 2022 Nov 14;61(46):e202211905. doi: 10.1002/anie.202211905. Epub 2022 Oct 18.
Membraneless organelles are droplets in the cytosol that are regulated by chemical reactions. Increasing studies suggest that they are internally organized. However, how these subcompartments are regulated remains elusive. Herein, we describe a complex coacervate-based model composed of two polyanions and a short peptide. With a chemical reaction cycle, we control the affinity of the peptide for the polyelectrolytes leading to distinct regimes inside the phase diagram. We study the transitions from one regime to another and identify new transitions that can only occur under kinetic control. Finally, we show that the chemical reaction cycle controls the liquidity of the droplets offering insights into how active processes inside cells play an important role in tuning the liquid state of membraneless organelles. Our work demonstrates that not only thermodynamic properties but also kinetics should be considered in the organization of multiple phases in droplets.
无膜细胞器是细胞质中的液滴，受化学反应调控。越来越多的研究表明，它们在内部是有组织的。然而，这些亚区室是如何被调控的仍然难以捉摸。在这里，我们描述了一个基于复杂凝聚物的模型，由两种聚阴离子和一个短肽组成。通过化学反应循环，我们控制肽与聚电解质的亲和力，导致相图中出现不同的状态。我们研究了从一个状态到另一个状态的转变，并确定了只有在动力学控制下才会发生的新转变。最后，我们表明化学反应循环控制着液滴的流动性，为细胞内的活性过程如何在调节无膜细胞器的液态状态方面发挥重要作用提供了新的认识。我们的工作表明，在液滴中多相的组织中，不仅要考虑热力学性质，还要考虑动力学。
