Karoui Hedi, Seck Marianne J, Martin Nicolas
Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal, UMR5031 115 Avenue du Dr Schweitzer 33600 Pessac France
Chem Sci. 2021 Jan 25;12(8):2794-2802. doi: 10.1039/d0sc06418a.
Membraneless organelles are phase-separated droplets that are dynamically assembled and dissolved in response to biochemical reactions in cells. Complex coacervate droplets produced by associative liquid-liquid phase separation offer a promising approach to mimic such dynamic compartmentalization. Here, we present a model for membraneless organelles based on enzyme/polyelectrolyte complex coacervates able to induce their own condensation and dissolution. We show that glucose oxidase forms coacervate droplets with a cationic polysaccharide on a narrow pH range, so that enzyme-driven monotonic pH changes regulate the emergence, growth, decay and dissolution of the droplets depending on the substrate concentration. Significantly, we demonstrate that time-programmed coacervate assembly and dissolution can be achieved in a single-enzyme system. We further exploit this self-driven enzyme phase separation to produce multiphase droplets dynamic polyion self-sorting in the presence of a secondary coacervate phase. Taken together, our results open perspectives for the realization of programmable synthetic membraneless organelles based on self-regulated enzyme/polyelectrolyte complex coacervation.
无膜细胞器是相分离的液滴,它们会根据细胞内的生化反应动态组装和溶解。通过缔合液-液相分离产生的复合凝聚液滴为模拟这种动态区室化提供了一种很有前景的方法。在此,我们提出了一种基于酶/聚电解质复合凝聚物的无膜细胞器模型,该凝聚物能够诱导自身的凝聚和溶解。我们发现葡萄糖氧化酶在狭窄的pH范围内与阳离子多糖形成凝聚液滴,因此酶驱动的单调pH变化会根据底物浓度调节液滴的出现、生长、衰减和溶解。值得注意的是,我们证明了在单酶系统中可以实现时间编程的凝聚物组装和溶解。我们进一步利用这种自驱动的酶相分离,在存在次级凝聚相的情况下产生多相液滴和动态聚离子自分选。综上所述,我们的结果为基于自我调节的酶/聚电解质复合凝聚作用实现可编程合成无膜细胞器开辟了前景。