Wang Renjie, Chen Qiaopeng, Zhang Rongjing, Yuan Junhua
Hefei National Laboratory for Physical Sciences at the Microscale, Hefei, Anhui, China; Department of Physics, University of Science and Technology of China, Hefei, Anhui, China.
Hefei National Laboratory for Physical Sciences at the Microscale, Hefei, Anhui, China; Department of Physics, University of Science and Technology of China, Hefei, Anhui, China.
Biophys J. 2020 Jun 2;118(11):2718-2725. doi: 10.1016/j.bpj.2020.04.020. Epub 2020 Apr 29.
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.
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性阻力，这包括丝上的摩擦粘性阻力（外部负载）和转子上的内部摩擦粘性阻力（内部负载）。内部负载先前通过将其建模为在粘度为100厘泊的脂质中旋转的半径为20纳米的球体进行了粗略估计，但从未通过实验测量过。在这里，我们通过对马达速度轨迹的波动分析测量了内部负载。类似的方法应该适用于其他分子马达。
