CHEMISTRY OF MUSCLE PROTEINS

目前关于肌肉收缩产生力量的步骤的理论包括 肌球蛋白头部相对于肌动蛋白细丝的重新定位 收缩周期。在这个模型中隐含着更多 肌球蛋白头部区域的一种构象状态。的一个主要目标 我们的研究继续阐明这种假定的结构 肌球蛋白重链和轻链亚基的变化。我们将继续追查 推进这一问题的两个主要方向：(1)特定标记，如 荧光探针、单抗和抗Small的抗体 多肽将被引入到明确的轻和重部位 锁链。抗体在肌球蛋白头部的位置将被可视化。 通过电子显微镜的阴影投射制剂。两地之间的距离 荧光团将通过福斯特能量转移进行测量。如有任何更改 与ATP和/或肌动蛋白结合的能量转移可以指示 头部的结构性变化。(2)中英关系的比较研究 差异很大的肌球蛋白同工酶的结构和功能可以提供 从任何一种肌球蛋白中都不能获得重要的见解。在肌球蛋白中 我们将继续研究成体肌球蛋白的快慢、胚胎和 禽类和哺乳动物的新生肌球蛋白和平滑肌肌球蛋白 消息来源。轻链去除或磷酸化对酶活性的影响 肌球蛋白的构象将被探索。技术将包括动能 分析、肽图谱、免疫学、电泳学和 沉淀物分析。通过研究这些肌球蛋白基因的多态 单体和丝状状态，我们可能最终会理解这是如何 复杂的分子起作用，以及为什么肌肉是由这样一个看似 纤维类型的无尽马赛克。

Current theories of the force generating step in muscle contraction involve a reorientation of the myosin head relative to the actin filament during the contractile cycle. Implicit in this model is the existence of more than one conformational state of the head region in myosin. A major aim of our research continues to be the elucidation of such putative structural changes in the heavy and light chain subunits of myosin. We will pursue two main directions to advance this problem: (1) Specific markers, such as fluorescent probes, monoclonal antibodies, and antibodies against small peptides will be introduced into well-defined sites on the light and heavy chains. The position of the antibody on the myosin head will be visualized by electron microscopy of shadow-cast preparations. Distances between fluorophores will be measured by Forster energy transfer. Any change in energy transfer with ATP and/or actin binding may be indicative of structural changes within the head. (2) Comparative studies on the structure and function of widely different myosin isozymes can provide important insights not obtainable from any one myosin. Among the myosins we will continue to study are fast and slow adult myosins, embryonic and neonatal myosins, and smooth muscle myosin from avian and mammalian sources. The effect of light chain removal or phosphorylation on the conformation of myosin will be explored. Techniques will include kinetic analysis, peptide mapping, immunological, electrophoretic, and sedimentation analysis. By investigating these myosin polymorphs both in the monomeric and filamentous state, we may eventually understand how this complex molecule works, and why muscle is composed of such a seemingly endless mosaic of fiber types.