TROPOMYOSIN IN MUSCLE REGULATION

这项研究的长期目标是了解 平滑肌原肌球蛋白在收缩调节中的作用。 虽然目前这一作用尚不清楚，但据认为， 原肌球蛋白的端对端相互作用在 监管的合作性质。 为了更好地理解 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规模的来源， 肌胃原肌球蛋白端-端相互作用异质性 通过羟基磷灰石色谱法观察。 该问题将被 通过使用包括粘度， 色谱、电泳、氨基酸分析，以及 沉淀 第二个具体目标是检验假设 原肌球蛋白的端对端相互作用是导致 合作行为 这将通过确定 不同末端对肌球蛋白影响 与肌动蛋白的相互作用 肌动球蛋白ATP酶活性的协同调节。 卡德蒙 一种新的平滑肌蛋白质，赋予细丝Ca 2 +- 对需要原肌球蛋白的调节的敏感性。 为了 了解这两种蛋白质的作用机制， 音乐会，这个项目的另一个目标是确定效果 原肌球蛋白，具有不同的端到端的相互作用， 钙调素与细丝的结合，并将其与 caldesmon对肌动球蛋白ATP酶活性的调节。 最后， 由于原肌球蛋白和钙调素之间的直接相互作用可能 在监管中发挥关键作用，这项拨款建议调查 原肌球蛋白之间的直接相互作用，具有不同的末端- 末端相互作用，以及具有粘度，自旋标记， 荧光标记、沉降和化学交联。

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.