Cells can control the assembly and disassembly of membraneless organelles by enzymatic processes, but similar control has not been achieved in vitro yet. Here we develop ATP-based coacervate droplets as artificial membraneless organelles that can be fully controlled by two cooperating enzymes. Droplets can be generated within a minute following the addition of phosphoenolpyruvate as a substrate, and they can be dissolved within tens of seconds by adding glucose as the second substrate. We show how the rates of droplet generation and dissolution can be tuned by varying the enzyme and substrate concentrations, and we support our findings with a kinetic model of the underlying enzymatic reaction network. As all steps of the coacervate droplet life cycle, including nucleation, coarsening, and dissolution, occur under the same reaction conditions, the cycle can be repeated multiple times. In addition, by carefully balancing the rates of both enzymatic reactions, our system can be programmed to either form or dissolve droplets at specified times, acting as a chemical timer.

中文翻译：

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在酶网络中可逆地产生凝聚层液滴†

细胞可以通过酶促过程控制无膜细胞器的组装和拆卸，但是在体外尚未实现类似的控制然而。在这里，我们开发了基于ATP的凝聚层液滴，将其作为可以由两种协同酶完全控制的人造无膜细胞器。在添加磷酸烯醇丙酮酸作为底物后的一分钟内可以产生液滴，并且通过添加葡萄糖作为第二底物可以将它们在数十秒内溶解。我们展示了如何通过改变酶和底物的浓度来调节液滴的产生和溶解的速率，并且我们用潜在的酶促反应网络的动力学模型来支持我们的发现。由于凝聚液滴生命周期的所有步骤（包括成核，粗化和溶解）都在相同的反应条件下发生，因此该循环可以重复多次。此外，通过仔细平衡两种酶促反应的速率，