A physical model of ATP-induced actin-myosin movement in vitro.
A physical model of ATP-induced actin-myosin movement in vitro.
复制标题
ATP 诱导的肌动蛋白-肌球蛋白体外运动的物理模型。
DOI：
10.1016/s0006-3495(91)82228-7
复制
发表时间：
1991
影响因子：
3.4
通讯作者：
K. Sekimoto
中科院分区：
文献类型：
--
作者：
K. Tawada;K. Sekimoto
考虑了限制 ATP 诱导的肌动蛋白丝体外单向运动速度的机制的性质。在滑动过程中，涉及肌球蛋白头和肌动蛋白之间的两种类型的“循环”相互作用，即生产性和非生产性。在富有成效的相互作用中，肌球蛋白头分裂 ATP 并产生在肌动蛋白和肌球蛋白之间产生滑动的力。另一方面，在非生产性相互作用“循环”中，肌球蛋白头“可逆地”快速附着和脱离肌动蛋白，即不分裂 ATP 或产生主动力。这种非生产性相互作用“循环”导致滑动能量不可逆地耗散成热量，因为在这种相互作用期间肌球蛋白跨桥是被动弹性结构。这种考虑使我们假设这种跨桥实际上对移动元件施加了类似粘性的摩擦阻力。能量方面的考虑表明，这种摩擦阻力比流体动力粘性阻力大得多。我们提出了一个模型，其中滑动速度受到生产性相互作用中肌球蛋白跨桥产生的力与非生产性相互作用中其他肌球蛋白跨桥施加的摩擦阻力之间的平衡的限制。该模型与体外滑动的实验结果一致，包括速度对 ATP 浓度的依赖性，以及骨骼肌肌球蛋白与磷酸化和非磷酸化平滑肌肌球蛋白的共聚物的滑动速度。
The nature of the mechanism limiting the velocity of ATP-induced unidirectional movements of actin-myosin filaments in vitro is considered. In the sliding process two types of "cyclic" interactions between myosin heads and actin are involved, i.e., productive and nonproductive. In the productive interaction, myosin heads split ATP and generate a force which produces sliding between actin and myosin. In the nonproductive interaction "cycle," on the other hand, myosin heads rapidly attach to and detach from actin "reversibly," i.e., without splitting ATP or generating an active force. Such a nonproductive interaction "cycle" causes irreversible dissipation of sliding energy into heat, because the myosin cross-bridges during this interaction are passive elastic structures. This consideration has led us to postulate that such cross-bridges, in effect, exert viscous-like frictional drag on moving elements. Energetic considerations suggest that this frictional drag is much greater than the hydrodynamic viscous drag. We present a model in which the sliding velocity is limited by the balance between the force generated by myosin cross-bridges in the productive interaction and the frictional drag exerted by other myosin cross-bridges in the nonproductive interaction. The model is consistent with experimental findings of in vitro sliding, including the dependence of velocity on ATP concentration, as well as the sliding velocity of co-polymers of skeletal muscle myosin and phosphorylated and unphosphorylated smooth muscle myosins.
影响因子：
--
作者：
HAI, CM;MURPHY, RA
通讯作者：
MURPHY, RA
DOI：
10.1073/pnas.83.17.6272
发表时间：
1986-09-01
影响因子：
11.1
作者：
KRON, SJ;SPUDICH, JA
通讯作者：
SPUDICH, JA