MYOSIN HEAD MOVEMENTS ARE SYNCHRONOUS WITH THE ELEMENTARY FORCE-GENERATING PROCESS IN MUSCLE
MYOSIN HEAD MOVEMENTS ARE SYNCHRONOUS WITH THE ELEMENTARY FORCE-GENERATING PROCESS IN MUSCLE
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DOI：
10.1038/357156a0
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发表时间：
1992-05-14
期刊：
影响因子：
64.8
通讯作者：
FERENCZI, MA
中科院分区：
文献类型：
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作者：
IRVING, M;LOMBARDI, V;FERENCZI, MA
运动蛋白如肌球蛋白、动力蛋白和驱动蛋白利用ATP水解的自由能产生力或运动，但尽管最近的进展1-4，它们的分子机制仍是未知的。最具特征的系统是肌球蛋白马达，它在肌肉5-12中移动肌动蛋白丝。当活跃的肌肉纤维迅速缩短时，力首先减小，然后在接下来的几毫秒内部分恢复。这种基本的力产生过程被认为是由于肌球蛋白头部结构域中的结构“工作行程”5-9，尽管结构研究尚未提供明确的支持10-12。X射线衍射表明，缩短的台阶使肌球蛋白头沿着细丝13、14的轴向重复产生的14.5 nm反射强度大大降低。这被解释为做功冲程结束时的结构变化，但当时可用的技术不允许基本力产生过程本身的时间分辨率。使用改进的测量技术，我们在这里表明，肌球蛋白头移动约10纳米的基本力产生过程相同的时间过程。
MOTOR proteins such as myosin, dynein and kinesin use the free energy of ATP hydrolysis to produce force or motion, but despite recent progress 1-4 their molecular mechanism is unknown. The best characterized system is the myosin motor which moves actin filaments in muscle 5-12. When an active muscle fibre is rapidly shortened the force first decreases, then partially recovers over the next few milliseconds 5. This elementary force-generating process is thought to be due to a structural 'working stroke' in the myosin head domain 5-9, although structural studies have not provided definitive support for this 10-12. X-ray diffraction has shown that shortening steps produce a large decrease in the intensity of the 14.5 nm reflection arising from the axial repeat of the myosin heads along the filaments 13,14 . This was interpreted as a structural change at the end of the working stroke, but the techniques then available did not allow temporal resolution of the elementary force-generating process itself. Using improved measurement techniques, we show here that myosin heads move by about 10 nm with the same time course as the elementary force-generating process.