Yokota E, Mabuchi I
Department of Biology, College of Arts and Sciences, University of Tokyo, Japan.
J Cell Sci. 1994 Feb;107 ( Pt 2):345-51. doi: 10.1242/jcs.107.2.345.
A novel dynein (C/A dynein), which is composed of C and A heavy chains, two intermediate chains and several light chains, was isolated from sea urchin sperm flagella. The C/A dynein was released by the treatment with 0.7 M NaCl plus 5 mM ATP from the axonemes depleted of outer arm 21 S dynein. Sedimentation coefficient of this dynein was estimated by sucrose density gradient centrifugation to be 22-23 S. The C/A dynein particle appeared to be composed of three distinct domains; two globular head domains and one rod domain as seen by negative staining electron microscopy. The mobility of 'A' heavy chain of C/A dynein on SDS-gel electrophoresis was similar to that of A heavy chains (A alpha and A beta) of 21 S dynein. However, UV-cleavage patterns of C and A heavy chains of C/A dynein were different from those of A heavy chains of 21 S dynein. Furthermore, an antiserum raised against A heavy chain of C/A dynein did not crossreact with A heavy chains of 21 S dynein. Under the conditions in which the C/A dynein was released, some of inner arms were removed concomitantly from axonemes as observed by electron microscopy. These results suggested that C/A dynein is a component of the inner arms.
一种由C和A重链、两条中间链和几条轻链组成的新型动力蛋白（C/A动力蛋白）从海胆精子鞭毛中分离出来。通过用0.7M NaCl加5mM ATP处理，从耗尽外臂21S动力蛋白的轴丝中释放出C/A动力蛋白。通过蔗糖密度梯度离心法估计该动力蛋白的沉降系数为22 - 23S。通过负染色电子显微镜观察，C/A动力蛋白颗粒似乎由三个不同的结构域组成；两个球状头部结构域和一个杆状结构域。C/A动力蛋白的“A”重链在SDS - 凝胶电泳上的迁移率与21S动力蛋白的A重链（Aα和Aβ）相似。然而，C/A动力蛋白的C和A重链的紫外线切割模式与21S动力蛋白的A重链不同。此外，针对C/A动力蛋白的A重链产生的抗血清与21S动力蛋白的A重链没有交叉反应。在释放C/A动力蛋白的条件下，通过电子显微镜观察发现，一些内臂会同时从轴丝上被去除。这些结果表明C/A动力蛋白是内臂的一个组成部分。
