Jones H M, Baskin R J, Yeh Y
Department of Zoology, University of California, Davis.
Biophys J. 1991 Nov;60(5):1217-28. doi: 10.1016/S0006-3495(91)82156-7.
The state of optical polarization of He-Ne laser light diffracted by single skinned frog skeletal muscle fibers has been determined after decoration of the thin filaments of rigor fibers with exogenous S-1. Light on the first diffraction order was analyzed using optical ellipsometry for changes occurring in total birefringence (delta nT) and total differential field ratio (rT) and the experimental results compared with theoretical predictions. Fibers were examined with SDS-gel electrophoresis and electron microscopy as independent assays of S-1 binding. The binding of S-1 to the thin filaments caused a significant increase in rT and a small but significant decrease in delta nT. Release of bound exogenous S-1 with magnesium pyrophosphate demonstrated that the effect of S-1 on the optical parameters was reversible and both electrophoresis and electron microscopy demonstrated the presence of S-1 specifically bound to the thin filaments. Model simulations based on the theory of Yeh, Y., and R. Baskin (1988. Biophys. J. 54:205-218) showed that the values of delta nT and rT were sensitive to the axial bonding angle of exogenous S-1 as well as to the volume fraction of added S-1. Analysis of the data in light of the model showed that an average axial S-1 binding angle of 68 degrees +/- 7 degrees best fit the data.
在用外源性S-1修饰僵直纤维的细肌丝后，测定了单皮层青蛙骨骼肌纤维衍射的氦氖激光的光偏振状态。使用椭圆偏振仪分析一级衍射光中总双折射（δnT）和总微分场比（rT）的变化，并将实验结果与理论预测进行比较。用SDS-凝胶电泳和电子显微镜检查纤维，作为S-1结合的独立检测方法。S-1与细肌丝的结合导致rT显著增加，δnT虽有小幅但显著的下降。用焦磷酸镁释放结合的外源性S-1表明，S-1对光学参数的影响是可逆的，电泳和电子显微镜都证明了S-1特异性结合在细肌丝上。基于Yeh, Y.和R. Baskin（1988年。《生物物理杂志》。54:205 - 218）理论的模型模拟表明，δnT和rT的值对外源性S-1的轴向结合角以及添加的S-1的体积分数敏感。根据该模型对数据的分析表明，平均轴向S-1结合角为68度±7度最符合数据。
