Structural changes in myosin cross-bridges during shortening of frog skeletal muscle
Structural changes in myosin cross-bridges during shortening of frog skeletal muscle
复制标题
青蛙骨骼肌缩短过程中肌球蛋白桥的结构变化
DOI：
10.1007/bf00125310
复制
发表时间：
1995
影响因子：
2.7
通讯作者：
S. Takemori
中科院分区：
文献类型：
--
作者：
N. Yagi;S. Takemori
在不同负荷下稳定缩短过程中记录了青蛙缝匠肌的 X 射线衍射图样。粗丝的第三次经向反射的强度在缩短时降低到与张力下降成比例的程度。强度与张力的相关性比与缩短速度的相关性更密切。第三次子午反射的布拉格间距与张力的减小成比例地减小。肌动蛋白层线在 1/5.1 和 1/5.9 nm−1 处的强度下降大致与负载的下降成正比，表明跨桥的数量也类似地下降。 (1,1) 赤道反射的强度仅在低负载时才显着降低。假设在稳定缩短过程中达到稳定的结构状态，结果与跨桥模型一致，其中肌球蛋白跨桥数量在缩短过程中减少。
X-ray diffraction patterns from frog sartorius muscle were recorded during steady shortening with various loads. The intensity of the third meridional reflection from the thick filament decreased on shortening to an extent proportional to the drop in tension. The intensity correlated more closely with the tension than with the shortening velocity. The Bragg spacing of the third meridional reflection decreased in proportion to the decrease in tension. The intensity decrease of the actin layer lines at 1/5.1 and 1/5.9 nm−1was roughly proportional to the decrease in the load, indicating that the number of cross-bridges decreases similarly. The intensity of the (1,1) equatorial reflection showed a significant decrease only with low loads. Assuming that a steady structural state is attained during steady shortening, the results are consistent with the cross-bridge model in which the number of myosin cross-bridges decreases during shortening.