Späth Fabian, Maier Anton S, Stasi Michele, Bergmann Alexander M, Halama Kerstin, Wenisch Monika, Rieger Bernhard, Boekhoven Job
Department of Chemistry, School of Natural Sciences, Technical University of Munich, Lichtenbergstrasse 4, 85748, Garching, Germany.
WACKER-Chair of Macromolecular Chemistry, Catalysis Research Center, Technical University of Munich, Lichtenbergstrasse 4, 85748, Garching, Germany.
Angew Chem Int Ed Engl. 2023 Oct 9;62(41):e202309318. doi: 10.1002/anie.202309318. Epub 2023 Sep 6.
Complex coacervation describes the liquid-liquid phase separation of oppositely charged polymers. Active coacervates are droplets in which one of the electrolyte's affinity is regulated by chemical reactions. These droplets are particularly interesting because they are tightly regulated by reaction kinetics. For example, they serve as a model for membraneless organelles that are also often regulated by biochemical transformations such as post-translational modifications. They are also a great protocell model or could be used to synthesize life-they spontaneously emerge in response to reagents, compete, and decay when all nutrients have been consumed. However, the role of the unreactive building blocks, e.g., the polymeric compounds, is poorly understood. Here, we show the important role of the chemically innocent, unreactive polyanion of our chemically fueled coacervation droplets. We show that the polyanion drastically influences the resulting droplets' life cycle without influencing the chemical reaction cycle-either they are very dynamic or have a delayed dissolution. Additionally, we derive a mechanistic understanding of our observations and show how additives and rational polymer design help to create the desired coacervate emulsion life cycles.
复合凝聚描述了带相反电荷的聚合物的液-液相分离。活性凝聚层是液滴，其中电解质的一种亲和力通过化学反应来调节。这些液滴特别有趣，因为它们受到反应动力学的严格调控。例如，它们可作为无膜细胞器的模型，而无膜细胞器也常常受到诸如翻译后修饰等生物化学转变的调控。它们也是很好的原细胞模型，或者可用于合成生命——它们会因应试剂而自发形成，在所有营养物质消耗殆尽时会竞争并衰退。然而，对于非反应性构建块（例如聚合物化合物）的作用，人们了解甚少。在此，我们展示了化学供能凝聚层液滴中化学性质惰性、无反应性的聚阴离子的重要作用。我们表明，聚阴离子极大地影响了所得液滴的生命周期，而不影响化学反应循环——它们要么非常活跃，要么溶解延迟。此外，我们对我们的观察结果有了机理上的理解，并展示了添加剂和合理的聚合物设计如何有助于创造所需的凝聚层乳液生命周期。
