TROPOMYOSIN AND MYOSIN INTERACTIONS IN MUSCLE

骨骼肌、心肌和平滑肌收缩的调节包括 所有事物内部和之间不断变化的交互作用的序列 细丝蛋白，还有肌球蛋白。一个主要的目标是学习如何 原肌球蛋白的构象性质与其功能有关。 以前的几种方法是利用荧光和自旋 放置在原肌球蛋白序列中特定残基的探针 用原肌球蛋白成功探测构象变化。这种方法 也涉及光滑和条纹之间的构象差异 原肌球蛋白活性的差异。 我们计划使用这些方法来研究 重组细丝系统中的原肌球蛋白 这些不同之处在于肌肉的“开”和“关”活动状态。这个 肌钙蛋白和肌球蛋白亚段1与标记的 原肌球蛋白-肌动蛋白细丝将允许自由能的差异 在不同的细丝状态之间待定。收费率 构象状态之间的波动将与 肌肉开始活动。不同化合物的构象性质 纹状原肌球蛋白(Alpha Alpha、Alpha Beta、Beta)和 将对ITS序列中接近不同的残基进行适当的研究 放置圆形二向色性和荧光标记。此外, 大鼠动脉平滑蛋白构象性质的差异 纹状原肌球蛋白也将被研究。此前，研究也是 开始研究肌球蛋白棒的部分构象性质，它将 可在下一个授权期内延长。Myosin路也有类似的结构 对原肌球蛋白包括方便定位的半胱氨酸残基 可用荧光探针标记和解释 沿线实验成功用于原肌球蛋白。它是 计划将肌球蛋白棒的构象特性与 在武力生成中可能扮演的角色。

The regulation of skeletal, cardiac and smooth muscle contraction involves a sequence of changing interaction within and between all of the thin filament proteins, and also of myosin. A major objective is to learn how the conformational properties of tropomyosin are related to its function. Previous several approaches were developed utilizing fluorescence and spin probes placed at a specific residue in tropomyosin's sequence to successfully probe conformational changes with tropomyosin. This approach also related conformational differences between smooth and striated tropomyosin to differences in activity. We plan to use these approaches to study conformational changes in tropomyosin in reconstituted thin filament systems with the aim of relating these differences to the "on" and "off" activity states of muscle. The binding of troponin and myosin sub-fragment 1 to the labeled tropomyosin-actin thin filament will allow differences in free energy between the different thin filament states to be determined. Rates of fluctuation between conformational states will be related to rates of switching on of muscle. The conformational properties of the different molecular forms of striated tropomyosin (Alpha Alpha, Alpha Beta, Beta) and near different residues along its sequence will be studied with suitably placed circular dichroism and fluorescence labels. In addition, differences between conformational properties of arterial smooth and striated tropomyosin will also be studied. Previously, studies were also begun on the conformational properties of portions of myosin rod which will be extended in the next grant period. Myosin road has a similar structure to tropomyosin including conveniently located Cys residues which make it amenable for labelling with fluorescence probes and interpreting experiments along the lines successfully used for tropomyosin. It is planned to relate the conformational properties of the myosin rod to possible roles in force generation.