Measurement of the Internal Frictional Drag of the Bacterial Flagellar Motor by Fluctuation Analysis
Measurement of the Internal Frictional Drag of the Bacterial Flagellar Motor by Fluctuation Analysis
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波动分析测量细菌鞭毛运动的内摩擦阻力
DOI：
10.1016/j.bpj.2020.04.020
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发表时间：
2020
影响因子：
3.4
通讯作者：
Yuan Junhua
中科院分区：
文献类型：
--
作者：
Wang Renjie;Chen Qiaopeng;Zhang Rongjing;Yuan Junhua
细菌鞭毛马达产生驱动细菌鞭毛丝旋转的扭矩。它产生的扭矩敏感地取决于马达上的摩擦粘滞阻力，其包括长丝上的摩擦粘滞阻力（外部负载）和转子上的内部摩擦粘滞阻力（内部负载）。先前通过将其建模为在100 cp粘度的脂质中旋转的半径为20 nm的球体来粗略估计内部负载，但从未通过实验测量。在这里，我们通过对电机速度轨迹的波动分析来测量内部负载。类似的方法应该适用于其他分子马达。
The bacterial flagellar motor generates the torque that drives the rotation of bacterial flagellar filaments. The torque it generates depends sensitively on the frictional viscous drag on the motor, which includes the frictional viscous drag on the filaments (external load) and the internal frictional viscous drag on the rotor (internal load). The internal load was roughly estimated previously by modeling it as a sphere of a radius of 20 nm rotating in a lipid of viscosity of 100 cp but was never measured experimentally. Here, we measured the internal load by fluctuation analysis of the motor velocity traces. A similar approach should be applicable to other molecular motors.