Bassir Kazeruni Neda M, Rodriguez Juan B, Saper Gadiel, Hess Henry
Columbia University, 351L Engineering Terrace, MC 8904 1210 Amsterdam Avenue, New York, New York 10027, United States.
Langmuir. 2020 Jul 14;36(27):7901-7907. doi: 10.1021/acs.langmuir.0c01002. Epub 2020 Jul 2.
The creation of complex active nanosystems integrating cytoskeletal filaments propelled by surface-adhered motor proteins often relies on the filaments' ability to glide over up to meter-long distances. While theoretical considerations support this ability, we show that microtubule detachment (either spontaneous or triggered by a microtubule crossing event) is a non-negligible phenomenon that has been overlooked until now. The average gliding distance before spontaneous detachment was measured to be 30 ± 10 mm for a functional kinesin-1 density of 500 μm and 9 ± 4 mm for a functional kinesin-1 density of 100 μm at 1 mM ATP. Even microtubules longer than 3 μm detached, suggesting that spontaneous detachment is not caused by the stochastic absence of motors or their stochastic release due to a limited run length.
整合由表面附着的运动蛋白推动的细胞骨架细丝的复杂活性纳米系统的构建通常依赖于细丝在长达一米的距离上滑动的能力。虽然理论上的考虑支持这种能力，但我们发现微管脱离（自发的或由微管交叉事件触发的）是一种至今被忽视但不可忽略的现象。在1 mM ATP条件下，对于功能驱动蛋白-1密度为500 μm的情况，自发脱离前的平均滑动距离测量为30±10 mm，对于功能驱动蛋白-1密度为100 μm的情况，平均滑动距离为9±4 mm。甚至超过3 μm长的微管也会脱离，这表明自发脱离不是由于运动蛋白的随机缺失或由于有限的运行长度导致的随机释放所引起的。
