Physical-Chemical Basis of the Contractile Mechanism

力是在肌肉收缩过程中由肌凝蛋白分子在缩短过程中拉动肌动蛋白丝而产生的。这一过程的细节很难确定，因为在细丝相对滑动期间发生的许多变化是迅速和不同步的。我们的工作集中在结构变化，被认为是发生在肌凝蛋白的头部区域在这种相互作用。近年来分子生物学技术的引入使我们能够修改肌球蛋白的多肽结构，从而使报告基团更容易被引入分子中。这些基团可以是用于光谱研究的荧光探针，也可以是用于电子显微镜直接可视化的电子密集探针。这些方法将提供关于ATP水解和肌动蛋白结合过程中肌球蛋白过桥运动动力学的新信息，无论是在单个分子中还是在肌肉收缩过程中的肌纤维中。

Force is developed in muscle contraction by myosin molecule pulling actin filaments during shortening. The details of this process have been difficult to establish because of the rapid and unsynchronized nature of the many changes taking place during the relative sliding of the filaments. Our work is focused on the structural changes that are thought to be occurring in the head region of myosin during this interaction. The introduction of molecular biological techniques in recent years has permitted us to modify the polypeptide structure of myosin in such a way that reporter groups can be more readily introduced into the molecule. These groups can be fluorescent probes for spectroscopic studies, or electron dense probes for direct visualization by electron microscopy. These methods should provide new information about the dynamics of myosin crossbridge movement during ATP hydrolysis and actin binding, both in individual molecules and in muscle fibers during muscle contraction.