Biased binding of single molecules and continuous movement of multiple molecules of truncated single-headed kinesin
Biased binding of single molecules and continuous movement of multiple molecules of truncated single-headed kinesin
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DOI：
10.1529/biophysj.104.049759
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发表时间：
2005-03-01
影响因子：
3.4
通讯作者：
Higuchi, H
中科院分区：
文献类型：
--
作者：
Kamei, T;Kakuta, S;Higuchi, H
传统的驱动蛋白具有由两个马达结构域组成的双头结构，并利用这两个头协同地沿微管向前沿着移动。利用激光陷阱和纳米探测装置对果蝇驱动蛋白的单个和多个截头的运动进行了测量。单头驱动蛋白的单分子与微管结合，并向微管的正端偏移3.5 nm。这些单头驱动蛋白分子结合到微管的位置没有改变，直到他们已经解离，表明单驱动蛋白头利用非进行性运动过程。两个单头驱动蛋白分子在微管中连续沿着运动，其运动速度和运动力均低于单个双头驱动蛋白分子。头部的偏向结合决定了运动的方向性，而两个单头驱动蛋白分子连续运动而不从微管中解离。
Conventional kinesin has a double-headed structure consisting of two motor domains and moves processively along a microtubule using the two heads cooperatively. The movement of single and multiple truncated heads of Drosophila kinesin was measured using a laser trap and nanometer detecting apparatus. Single molecules of single-headed kinesin bound to the microtubules with a 3.5 nm biased displacement toward the plus end of the microtubule. The position of these single-headed kinesin molecules bound to a microtubule did not change until they had dissociated, indicating that single kinesin heads utilize nonprocessive movement processes. Two molecules of single-headed kinesin moved continuously along a microtubule with a lower velocity and force than that of single molecules of double-headed kinesin. The biased binding of the heads determines the directionality of movement, whereas two molecules of single-headed kinesin move continuously without dissociation from a microtubule.