Yeh Y, Baskin R J
Department of Applied Science, University of California, Davis 95616.
Biophys J. 1988 Aug;54(2):205-18. doi: 10.1016/S0006-3495(88)82949-7.
A theory of optical ellipsometry describing the complete phase shift and ellipticity of light diffracted from a single muscle fiber is developed. We show that both the phase shift information, described commonly by the birefringence of the fiber, and the ellipticity information, described by the differential polarizability ratio, are necessary to provide a complete picture of the complex contributions to the total optical anisotropy spectra from a diffraction pattern derived from the striated muscle cell. Both form and intrinsic contributions play significant roles in either the birefringence measurement or the differential field ratio measurement. However, we show that their relative weights in these two measured quantities are different, and measuring both of these parameters is necessary to obtain a more complete assessment of the cross-bridge structure and dynamics. The theoretical results have been tested for three different situations: solvent index matching, passive stretch of a resting fiber, and cross-bridge changes under isometric conditions. Comparisons between experimental data and simple model calculations provide much information regarding cross-bridge orientation and structure.
本文提出了一种光学椭圆偏振测量理论，用于描述从单根肌纤维衍射的光的完整相移和椭圆率。我们表明，通常由纤维双折射描述的相移信息以及由微分极化率比描述的椭圆率信息，对于全面了解横纹肌细胞衍射图案对总光学各向异性光谱的复杂贡献是必要的。形态贡献和内在贡献在双折射测量或微分场比测量中都起着重要作用。然而，我们表明它们在这两个测量量中的相对权重不同，测量这两个参数对于更全面地评估横桥结构和动力学是必要的。理论结果已在三种不同情况下进行了测试：溶剂折射率匹配、静息纤维的被动拉伸以及等长条件下的横桥变化。实验数据与简单模型计算之间的比较提供了许多关于横桥取向和结构的信息。
