Kabir Arif Md Rashedul, Munmun Tasrina, Sada Kazuki, Kakugo Akira
Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.
Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-0810, Japan.
ACS Omega. 2022 May 23;7(22):18597-18604. doi: 10.1021/acsomega.2c01228. eCollection 2022 Jun 7.
Nowadays, biomolecular motor-based miniaturized lab-on-a-chip devices have been attracting much attention for their wide range of nanotechnological applications. Most of the applications are dependent on the motor-driven active transportation of their associated filamentous proteins as shuttles. Fluctuation in the movement of the shuttles is a major contributor to the dispersion in motor-driven active transportation, which limits the efficiency of the miniaturized devices. In this work, by employing the biomolecular motor kinesin and its associated protein filament microtubule as a model active transport system, we demonstrate that the deep-sea osmolyte trimethylamine -oxide (TMAO) is useful in regulating the fluctuation in the motility of microtubule shuttles. We show that the motional diffusion coefficient, a measure of the fluctuation in the movement of the kinesin-propelled microtubules, gradually decreases upon increasing the concentration of TMAO in the transportation system. We have been able to reduce the motional diffusion coefficient of microtubules more than 200 times by employing TMAO at a concentration of 2 M. We also show that upon elimination of TMAO, the motional diffusion coefficient of microtubules can be restored, which confirms that TMAO can be used as a tool to reversibly regulate the fluctuation in the sliding movement of kinesin-propelled microtubule shuttles. Such reversible regulation of the dynamic behavior of the shuttles does not require sacrificing the concentration of fuel used for transportation. Our results confirm the ability to manipulate the nanoscale motion of biomolecular motor-driven active transporters in an artificial environment. This work is expected to further enhance the tunability of biomolecular motor functions, which, in turn, will foster their nanotechnological applications based on active transportation.
如今，基于生物分子马达的微型芯片实验室装置因其广泛的纳米技术应用而备受关注。大多数应用依赖于马达驱动其相关丝状蛋白作为穿梭体的主动运输。穿梭体运动的波动是马达驱动主动运输中分散现象的主要原因，这限制了微型装置的效率。在这项工作中，通过将生物分子马达驱动蛋白和其相关的蛋白丝微管作为模型主动运输系统，我们证明深海渗透剂三甲胺氧化物（TMAO）可用于调节微管穿梭体运动的波动。我们表明，运动扩散系数是衡量驱动蛋白推动的微管运动波动的指标，在运输系统中增加TMAO浓度时，该系数会逐渐降低。通过使用浓度为2 M的TMAO，我们能够将微管的运动扩散系数降低200倍以上。我们还表明，去除TMAO后，微管的运动扩散系数可以恢复，这证实TMAO可作为一种工具来可逆地调节驱动蛋白推动的微管穿梭体滑动运动的波动。这种对穿梭体动态行为的可逆调节不需要牺牲用于运输的燃料浓度。我们的结果证实了在人工环境中操纵生物分子马达驱动的主动转运体纳米级运动的能力。这项工作有望进一步提高生物分子马达功能的可调性，进而促进基于主动运输的纳米技术应用。
