Ishijima A, Kojima H, Funatsu T, Tokunaga M, Higuchi H, Tanaka H, Yanagida T
Biomotron Project, ERATO, JST, Mino, Osaka, Japan.
Cell. 1998 Jan 23;92(2):161-71. doi: 10.1016/s0092-8674(00)80911-3.
We have developed a technique that allows mechanical and ligand-binding events in a single myosin molecule to be monitored simultaneously. We describe how steps in the ATPase reaction are temporally related to mechanical events at the single molecule level. The results show that the force generation does not always coincide with the release of bound nucleotide, presumably ADP. Instead the myosin head produces force several hundreds of milliseconds after bound nucleotide is released. This finding does not support the widely accepted view that force generation is directly coupled to the release of bound ligands. It suggests that myosin has a hysteresis or memory state, which stores chemical energy from ATP hydrolysis.
我们开发了一种技术，可同时监测单个肌球蛋白分子中的机械事件和配体结合事件。我们描述了ATP酶反应中的步骤在单分子水平上如何与机械事件在时间上相关。结果表明，力的产生并不总是与结合核苷酸（推测为ADP）的释放同时发生。相反，肌球蛋白头部在结合核苷酸释放后数百毫秒才产生力。这一发现不支持广泛接受的观点，即力的产生直接与结合配体的释放相耦合。它表明肌球蛋白具有滞后或记忆状态，该状态存储来自ATP水解的化学能。
