Beijing National Laboratory for Molecular Sciences, MOE Key Laboratory of Polymer Chemistry and Physics, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
Soft Matter. 2018 Aug 21;14(31):6514-6520. doi: 10.1039/c8sm01168k. Epub 2018 Jul 27.
Artificial protocells operating under non-equilibrium conditions offer a new approach to achieve dynamic features with life-like properties. Using coacervate micro-droplets comprising polylysine (PLL) and a short single-stranded oligonucleotide (ss-oligo) as a membrane-free protocell model, we demonstrate that circulation and vacuolization can occur simultaneously inside the droplet in the presence of an electric field. The circulation is driven by electrohydrodynamics and applies specifically to the major components of the protocell (PLL and ss-oligo). Significantly, under low electric fields (E = 10 V cm) the circulation regulates the movement of the vacuoles, while high levels of vacuolization produced at higher electric fields can deform or reshape the circulation. By taking advantage of the interplay between vacuolization and circulation, we achieve dynamic localization of an enzyme cascade reaction at specific droplet locations. In addition, the spatial distribution of the enzyme reaction is globalized throughout the droplet by tuning the coupling of the circulation and vacuolization processes. Overall, our work provides a new strategy to create non-equilibrium dynamic behaviors in molecularly crowded membrane-free synthetic protocells.
在非平衡条件下运行的人工原细胞为实现具有类似生命特性的动态特征提供了一种新方法。我们使用包含多聚赖氨酸 (PLL) 和短单链寡核苷酸 (ss-oligo) 的凝聚体微滴作为无膜原细胞模型，证明在电场存在的情况下，滴内可以同时发生循环和空化。循环是由电动流体动力学驱动的，并且特别适用于原细胞的主要成分（PLL 和 ss-oligo）。重要的是，在低电场 (E = 10 V cm) 下，循环调节空泡的运动，而在更高的电场下产生的高水平空化可以使循环变形或重塑。通过利用空化和循环之间的相互作用，我们实现了酶级联反应在特定液滴位置的动态定位。此外，通过调整循环和空化过程的耦合，可以使酶反应的空间分布在整个液滴中全局化。总的来说，我们的工作为在分子拥挤的无膜合成原细胞中产生非平衡动态行为提供了一种新策略。
