Optical depolarization changes on the diffraction pattern in the transition of skinned muscle fibers from relaxed to rigor state.
Optical depolarization changes on the diffraction pattern in the transition of skinned muscle fibers from relaxed to rigor state.
复制标题
蒙皮肌纤维从松弛状态转变为僵硬状态时，衍射图案上的光学去偏振发生变化。
DOI：
10.1016/s0006-3495(83)84308-2
复制
发表时间：
1983
影响因子：
3.4
通讯作者：
Lieber,RL
中科院分区：
文献类型：
--
作者：
Yeh,Y;Corcoran,ME;Baskin,RJ;Lieber,RL
光衍射光谱从单个或小束的皮肤横纹肌纤维显示大的变化时，肌肉被放置到僵硬的偏振特性。结合光学衍射和椭圆偏振测量的技术先前已被Yeh和Pinsky证明是光纤周期性各向异性区域的灵敏探针。在目前的工作中，使用这种方法，所观察到的光谱显示出显着的减少，在测量的相位角，δ，作为纤维接近僵硬状态。相位角变化的程度是肌节长度的函数：对于一束三根纤维，约2.3微米的最大重叠给出了最大的Δ R-R变化，Δ Δ R-R减小约35度。在肌节长度为2.9微米时，该Δ Δ R-R值仅为10度。在约3.8微米的非重叠长度处，在去除ATP时，Δ根本不变化。通过在小幅度（0.75%）快速长度变化后进行的刚度测量确认了僵硬状态。在再松弛时，结皮纤维的刚度降低到静息状态的值（4 mM ATP），并且相位角δ返回到其原始值。一个模型的基础上，无论是各向异性的亚基-2（S-2）的运动或其他跨桥相关的结构各向异性（形式双折射）的变化，在松弛-严谨的过渡。
Light diffraction spectra from single or small bundles of skinned striated muscle fibers show large changes in polarization properties when muscles are placed into rigor. The technique of combining optical diffraction and ellipsometry measurements has previously been shown by Yeh and Pinsky to be a sensitive probe of periodic anisotropic regions of the fiber. In the present work, using this method, the observed spectrum shows marked decrease in the measured phase angle, delta, as the fiber approaches the rigor state. The degree of phase angle change is a function of sarcomere length: Maximum overlap of approximately 2.3 microns gives the most change in delta a delta delta R-R approximately 35 degrees decrease for a bundle of three fibers. At a sarcomere length of 2.9 microns this delta delta R-R value is only 10 degrees. At a nonoverlapping length of approximately 3.8 microns, delta does not vary at all upon the removal of ATP. The rigor state was confirmed by stiffness measurements made after small-amplitude (0.75%), quick length changes. Upon re-relaxation, the stiffness of the skinned fiber decreased to the value of the resting state (4 mM ATP) and the phase angle delta returned to its original value. A model based on either anisotropic subunit-2 (S-2) movements or other cross-bridge-related structural anisotropy (form birefringence) changes during the relaxed-rigor transition is suggested.