School of Life Science and Technology, Tokyo Institute of Technology , 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan.
Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency , 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
J Am Chem Soc. 2017 Dec 13;139(49):18016-18023. doi: 10.1021/jacs.7b09515. Epub 2017 Nov 27.
Mechanical stress is a ubiquitous stimulus sensed by membrane proteins, but rarely by synthetic molecules. Inspired by mechano-sensitive ion channels found in cell membranes, tension-responsive transmembrane multiblock amphiphiles were developed. In membranes, a single-transmembrane amphiphile responds to both expanding and contracting tensions to weaken and strengthen the stacking of membrane-spanning units, respectively, and ion transportation is triggered by expanding tension to form a supramolecular channel, while little transportation is observed under a tensionless condition. In contrast, a three-transmembrane amphiphile showed little spectroscopic response to tensions, likely due to weaker stacking of membrane-spanning units than in the single-transmembrane amphiphile. Nevertheless, the three-transmembrane amphiphile shows ion transportation by forming a unimolecular channel even under a tensionless condition, and the ion-transporting activity decreased with expanding tension. Interestingly, the estimated operating force of these synthetic systems was comparable to that of the mechano-sensitive proteins. This study opens the door toward new mechano-sensitive molecular devices.
机械应力是一种普遍存在的刺激，可被细胞膜蛋白感知，但很少被合成分子感知。受细胞膜中机械敏感离子通道的启发，开发了对张力响应的跨膜多嵌段两亲物。在膜中，单一跨膜两亲物对扩张和收缩张力都有响应，分别削弱和增强膜贯穿单元的堆积，并且离子传输是由扩张张力触发的，以形成超分子通道，而在无张力条件下几乎观察不到传输。相比之下，三跨膜两亲物对张力的光谱响应很小，可能是由于膜贯穿单元的堆积比单一跨膜两亲物弱。然而，三跨膜两亲物即使在无张力条件下也通过形成单分子通道来进行离子传输，并且离子传输活性随着扩张张力的增加而降低。有趣的是，这些合成系统的估计操作力与机械敏感蛋白相当。这项研究为新型机械敏感分子器件开辟了道路。
