Research on the driving, lubrication and self assembled mechanism of bacterial flagellar motor

本研究对细菌鞭毛马达的驱动、润滑和自组装机理进行了研究，以期建立新的纳米机器结构原理。在纳米尺度下，各种物理效应对机械的驱动、润滑和自组装机制起着至关重要的作用。在研究开始时，我们并不知道构建非机器的指导原则。细菌有鞭毛马达，有时被称为活纳米机器，因为它有马达、轴颈轴承、万向节和螺钉。我们的主要想法是获得细菌鞭毛马达的精确机制，并将这些机制应用于纳米机器的驱动、润滑和自组装系统。在之前的研究中，我们估计了细菌鞭毛的润滑机制。利用经典流体动力润滑理论，计算了负载电容。由此产生的负载电容为0.1pN数量级（× 10^<-12>N），该值不足以补偿驱动力（0.5pN）。此外，杆与轴颈之间的分子间作用力为10^2pN数量级，远远大于驱动力产生的负载。因此，我们得出结论，必须引入新的润滑机制来解释PL环的行为。我们提出使用扩散双层作为润滑机制的可能候选。我们估计了由这种效应产生的负载电容，并表明这种机制可以获得足够的排斥力。我们利用被称为疏水胶体溶液稳定性来源的扩散双层效应，制定了新的润滑机制。结果表明，该机构不仅提供了足够的负载电容来补偿轴向和径向轴颈之间的各种作用力，而且还提供了自组装系统的驱动力。

In this research, we investigated the driving, lubrication and self assembled mechanism of bacterial flagellar motor in order to develop new principle of nanomachine architecture. In nanoscale world, different kind of physical effects have essential roles on driving, lubrication and self assembled mechanism of machines. We did not know the guiding principle to construct nonomachine at the starting point of the study. Bacterial having flagellar motor sometimes called living nanomachine as it has motor, journal bearing universal joint and screw. Our main idea is to get the precise knowledge of the mechanism of bacterial flagellar motor and utilizing these mechanisms to the driving, lubrication and self assembled system of nanomachines.In a previous study, we estimated lubrication mechanism of bacterial flagellar. By using theory of the classical hydrodynamic lubrication, we calculated load capacitance. Resulting load capacitance is order of 0.1pN( x 10^<-12>N) and this values is not adequate to compensate driving force (0.5pN) Furthermore, intermolecular force between rod and journal becomes order of 10^2pN that is far bigger than load generated by driving force.Thus, we concluded that new lubrication mechanism must be introduced to explain the behavior of PL ring. We proposed use of diffusive double layer as possible candidate of lubrication mechanism. We estimated the load capacitance generated by this effect and showed the adequate amount of repulsive force can be obtained by this mechanism.We formulated new lubrication mechanism using the effects of diffusive double layer that is known as the origin of stability in hydrophobic colloidal solution. It is shown that this mechanism not only gives enough load capacitance to compensate the various forces between journal of rod in axial and radial direction but also gives driving force of self assembled system.