TROPOMYOSIN IN MUSCLE REGULATION

这项研究的长期目标是理解 原肌球蛋白在调节收缩中的作用。 尽管目前还不清楚这一角色，但人们认为 原肌球蛋白的端到端相互作用在 监管的合作性。为了更好地了解 这种端到端相互作用的分子基础，一个特定的目标 这项建议的目的是调查大量 肌球蛋白端到端相互作用的异质性 羟基磷灰石层析观察。这个问题将是 通过使用几种技术来解决，包括粘度， 层析、电泳法、氨基酸分析和 沉积作用。第二个具体目标是检验这一假设 原肌球蛋白的端到端相互作用是其 合作行为。这将通过确定 不同端到端肌球蛋白对肌球蛋白的影响 肌动蛋白与肌动蛋白协同结合的相互作用 肌动球蛋白ATPase活性的协同调节。卡尔德斯蒙 一种新的平滑肌蛋白，赋予细丝钙- 对需要原肌球蛋白的调节敏感。为了 了解这两种蛋白质的作用机制 演唱会，这个项目的另一个目标是确定效果 具有不同端到端相互作用的原肌球蛋白 钙结合蛋白与细丝的结合及其相互关系 钙调素对肌动球蛋白ATPase活性的调节。最后， 由于原肌球蛋白和钙调蛋白之间的直接相互作用可能 在监管中发挥关键作用，这笔拨款建议调查 原肌球蛋白之间的直接相互作用，具有不同的端到端 末端相互作用，以及钙离子与粘度，自旋标记， 荧光标记、沉淀和化学交联剂。

The long-term objective of this research is to understand the role of smooth muscle tropomyosin in the regulation of contraction. Although this role is presently unclear, it is thought that tropomyosin's end-to-end interaction plays a key part in the cooperative nature of regulation. In order to better understand the molecular basis of this end-to-end interaction, a specific goal of this proposal is to investigate the source of the large heterogeneity in gizzard tropomyosin's end-to-end interaction observed by hydroxylapatite chromatography. This question will be addressed by using several techniques including viscosity, chromatography, electrophoresis, amino acid analysis, and sedimentation. A second specific aim is to test the hypothesis that tropomyosin's end-to-end interaction is responsible for its cooperative behavior. This will be accomplished by determining the effect of gizzard tropomyosin with different end-to-end interactions on its cooperative binding to actin and its cooperative regulation of actomyosin ATPase activity. Caldesmon, a new smooth muscle protein, imparts a thin filament Ca2+- sensitivity to regulation which requires tropomyosin. In order to understand the mechanism thereby these two proteins work in concert, another goal of this project is to determine the effect of tropomyosin, with different end-to-end interactions, on the binding of caldesmon to the thin filament and correlate this with caldesmon's regulation of actomyosin ATPase activity. Finally, since the direct interaction between tropomyosin and caldesmon may play a key role in regulation, this grant proposes to investigate the direct interaction between tropomyosin, with different end-to- end interactions, and caldesmon with viscosity, spin labels, fluorescence labels, sedimentation, and chemical cross-linking.