Kensler R W, Stewart M
J Cell Biol. 1983 Jun;96(6):1797-802. doi: 10.1083/jcb.96.6.1797.
A procedure has been developed for isolating and negatively staining vertebrate skeletal muscle thick filaments that preserves the arrangement of the myosin crossbridges. Electron micrographs of these filaments showed a clear periodicity associated with crossbridges with an axial repeat of 42.9 nm. Optical diffraction patterns of these images showed clear layer lines and were qualitatively similar to published x-ray diffraction patterns, except that the 1/14.3-nm meridional reflection was somewhat weaker. Computer image analysis of negatively stained images of these filaments has enabled the number of strands to be established unequivocally. Both reconstructed images from layer line data and analysis of the phases of the inner maxima of the first layer line are consistent only with a three-stranded structure and cannot be reconciled with either two- or four-stranded models.
已开发出一种用于分离和负染脊椎动物骨骼肌粗肌丝的方法，该方法可保留肌球蛋白横桥的排列。这些肌丝的电子显微照片显示出与横桥相关的清晰周期性，轴向重复距离为42.9纳米。这些图像的光学衍射图谱显示出清晰的层线，并且在质量上与已发表的X射线衍射图谱相似，只是1/14.3纳米的子午线反射稍弱一些。对这些肌丝的负染图像进行计算机图像分析，能够明确确定链的数量。从层线数据重建的图像以及对第一层线内部最大值相位的分析都仅与三链结构一致，无法与双链或四链模型相协调。
