Dichroic behavior of the absorbance signals from dyes NK2367 and WW375 in skeletal muscle fibers.
Dichroic behavior of the absorbance signals from dyes NK2367 and WW375 in skeletal muscle fibers.
复制标题
DOI：
10.1085/jgp.84.5.805
复制
发表时间：
1984-11
期刊：
影响因子：
--
通讯作者：
Vergara J
中科院分区：
文献类型：
--
作者：
Heiny JA;Vergara J
从用非穿透电位染料NK 2367和WW 375染色的电压钳位单肌纤维记录吸光度信号，并用560至800 nm的准单色光照射，线性偏振平行（0度）或垂直（90度）于纤维长轴。来自两种染料的信号强烈地依赖于入射偏振。在任何波长和/或偏振条件下，总吸光度信号是先前用非偏振光识别的相同的两个信号分量的叠加（Heiny，J.A.，和J. Vergara，1982，J. Gen. Physiol.，80：203）--即，来自电压钳位表面膜的快速步进信号和反映较慢T系统电位变化的信号。两种膜的0度和90度光谱具有相似的正吸收峰和负吸收峰（染料NK 2367分别为720和670 nm;染料WW 375分别为740和700 nm）;此外，它们具有相同的二色性最大值（NK 2367为670; WW 375为700）。然而，对于表面膜，0度光谱到处都比90度光谱更正，而T系统则相反，这导致两个膜的二色性符号相反。使用吸收染料的电位依赖性响应的一般模型分析这些光谱特性（Tasaki，I.，和A. Warashina，1976，Photochem.光生物学，24：191），其考虑了染料响应和膜几何形状。它们与染料通过两种膜中的共同机制做出反应的提议一致，该机制包括染料重新取向和吸收最大值的变化。
Absorbance signals were recorded from voltage-clamped single muscle fibers stained with the nonpenetrating potentiometric dyes NK2367 and WW375 and illuminated with quasimonochromatic light from 560 to 800 nm, linearly polarized either parallel (0 degree) or perpendicular (90 degrees) to the fiber long axis. The signals from both dyes depend strongly on the incident polarization. At any wavelength and/or polarization condition, the total absorbance signal is a superposition of the same two signal components previously identified with unpolarized light (Heiny, J. A., and J. Vergara, 1982, J. Gen. Physiol., 80:203)--namely, a fast step signal from the voltage-clamped surface membrane and a signal reflecting the slower T-system potential changes. The 0 degree and 90 degrees spectra of both membranes have similar positive and negative absorbance peaks (720 and 670 nm, respectively, for dye NK2367; 740 and 700 nm for dye WW375); in addition, they have the same dichroic maxima (670 for NK2367; 700 for WW375). However, for the surface membrane, the 0 degrees spectra are everywhere more positive than the 90 degrees spectra, whereas the reverse is true for the T-system, which results in a dichroism of opposite sign for the two membranes. These spectral characteristics were analyzed using a general model for the potential-dependent response of an absorbing dye (Tasaki, I., and A. Warashina, 1976, Photochem. Photobiol., 24:191), which takes into account both the dye response and the membrane geometries. They are consistent with the proposal that the dye responds via a common mechanism in both membranes that consists of a dye reorientation and a change in the absorption maxima.