Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, USA.
Department of Chemistry, The Pennsylvania State University, University Park, PA, USA.
Nat Nanotechnol. 2019 Dec;14(12):1129-1134. doi: 10.1038/s41565-019-0578-8. Epub 2019 Nov 18.
The ability of cells or cell components to move in response to chemical signals is critical for the survival of living systems. This motion arises from harnessing free energy from enzymatic catalysis. Artificial model protocells derived from phospholipids and other amphiphiles have been made and their enzymatic-driven motion has been observed. However, control of directionality based on chemical cues (chemotaxis) has been difficult to achieve. Here we show both positive or negative chemotaxis of liposomal protocells. The protocells move autonomously by interacting with concentration gradients of either substrates or products in enzyme catalysis, or Hofmeister salts. We hypothesize that the propulsion mechanism is based on the interplay between enzyme-catalysis-induced positive chemotaxis and solute-phospholipid-based negative chemotaxis. Controlling the extent and direction of chemotaxis holds considerable potential for designing cell mimics and delivery vehicles that can reconfigure their motion in response to environmental conditions.
细胞或细胞成分响应化学信号而移动的能力对于生命系统的生存至关重要。这种运动源于利用酶催化产生的自由能。已经制备了源自磷脂和其他两亲物的人工模型原细胞，并观察到了它们的酶促运动。然而，基于化学线索（趋化性）的方向控制一直难以实现。在这里，我们展示了脂质体原细胞的正向或负向趋化性。原细胞通过与酶催化中底物或产物的浓度梯度或霍夫迈斯特盐相互作用而自主运动。我们假设推进机制基于酶催化诱导的正向趋化性和基于溶质-磷脂的负向趋化性之间的相互作用。控制趋化性的程度和方向对于设计可以根据环境条件重新配置运动的细胞模拟物和输送载体具有相当大的潜力。
