Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands.
Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
Nat Chem. 2018 Feb;10(2):132-138. doi: 10.1038/nchem.2887. Epub 2017 Dec 4.
A striking feature of living systems is their ability to produce motility by amplification of collective molecular motion from the nanoscale up to macroscopic dimensions. Some of nature's protein motors, such as myosin in muscle tissue, consist of a hierarchical supramolecular assembly of very large proteins, in which mechanical stress induces a coordinated movement. However, artificial molecular muscles have often relied on covalent polymer-based actuators. Here, we describe the macroscopic contractile muscle-like motion of a supramolecular system (comprising 95% water) formed by the hierarchical self-assembly of a photoresponsive amphiphilic molecular motor. The molecular motor first assembles into nanofibres, which further assemble into aligned bundles that make up centimetre-long strings. Irradiation induces rotary motion of the molecular motors, and propagation and accumulation of this motion lead to contraction of the fibres towards the light source. This system supports large-amplitude motion, fast response, precise control over shape, as well as weight-lifting experiments in water and air.
生命系统的一个显著特征是，它们能够通过从纳米尺度到宏观尺度的集体分子运动的放大来产生运动性。一些天然的蛋白质马达，如肌肉组织中的肌球蛋白，由非常大的蛋白质的分层超分子组装组成，其中机械应力诱导协调运动。然而，人工分子肌肉往往依赖于共价聚合物基致动器。在这里，我们描述了由光响应两亲性分子马达的分级自组装形成的超分子系统（包含 95%的水）的宏观收缩型肌肉样运动。分子马达首先组装成纳米纤维，进一步组装成排列成束的纤维，这些纤维构成了数厘米长的字符串。辐照诱导分子马达的旋转运动，并且这种运动的传播和积累导致纤维朝着光源收缩。该系统支持大振幅运动、快速响应、对形状的精确控制，以及在水和空气中的举重实验。
