• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Molecular Biology >Orientational information of troponin C within the thin filaments obtained by neutron fiber diffraction.
【24h】

Orientational information of troponin C within the thin filaments obtained by neutron fiber diffraction.

机译：通过中子纤维衍射获得的细丝中肌钙蛋白C的取向信息。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In striated muscles contraction is regulated by the thin filament-based proteins, troponin consisting of three subunits (TnC, TnI, and TnT), and tropomyosin. Knowledge of in situ structures of these proteins is indispensable for elucidating this Ca(2+)-sensitive regulatory mechanism. We employed neutron scattering to investigate the structure of TnC within the thin filament, and found that TnC assumes extended dumbbell-like structures and moves toward the filament axis by binding of Ca(2+). Here, in order to obtain more detailed in situ structural information of TnC, neutron fiber diffraction measurements were performed. Sols of native thin filaments and the thin filaments containing deuterated TnC were prepared in (2)H(2)O. The oriented samples were obtained by placing these sols sealed in quartz capillaries with a diameter of 3 mm in a magnetic field of 18 Tesla. Neutron fiber diffraction patterns were obtained from these oriented samples in the absence and presence of Ca(2+). The patterns obtained showed strong equatorial diffraction due to the thin filaments, 59 A and 51 A layer-lines due to actin, and meridional reflections due to Tn-complex. Analysis of the meridional reflections due to Tn-complex with aid of model calculation showed that the angle between the thin filament axis and the long axis of TnC was estimated to be 67(+/-7) degrees and 49(+/-17) degrees , in the absence and presence of Ca(2+), respectively, suggesting that TnC, which assumes orientations rather perpendicular to the filament axis in the absence of Ca(2+), tilts toward the filament axis and the orientational and positional disorder increases by binding Ca(2+). It also showed that the relative position of the TnC moved by about 22 A by binding Ca(2+), and this apparent movement was concomitant with the movements of other Tn-subunits. This implies that by binding Ca(2+), significant structural rearrangements of Tn-subunits occur.
机译：在横纹肌中，收缩由细丝状蛋白，由三个亚基（TnC，TnI和TnT）组成的肌钙蛋白和原肌球蛋白调节。这些蛋白质的原位结构的知识对于阐明这种Ca（2+）敏感的调节机制是必不可少的。我们使用中子散射来研究细细丝内TnC的结构，并发现TnC呈延长的哑铃状结构并通过Ca（2+）的结合而向细丝轴移动。在这里，为了获得更详细的TnC原位结构信息，进行了中子纤维衍射测量。在（2）H（2）O中制备天然细丝和含有氘化TnC的细丝的溶胶。通过将这些溶胶密封在直径为3 mm的石英毛细管中，在18 Tesla磁场中获得定向样品。在不存在和存在Ca（2+）的情况下，从这些定向样品获得中子纤维衍射图。由于细丝，因肌动蛋白引起的59 A和51 A层线以及因Tn络合物引起的子午反射，所获得的图形显示出强烈的赤道衍射。通过模型计算分析了Tn络合物引起的子午反射，表明细丝轴与TnC长轴之间的夹角估计为67（+/- 7）度和49（+/- 17）度度，分别在不存在和存在Ca（2+）的情况下，表明TnC在不存在Ca（2+）的情况下呈现与长丝轴相当垂直的方向，向着长丝轴倾斜，并且取向和位置无序通过绑定Ca（2+）增加。它还表明，TnC的相对位置通过结合Ca（2+）移动了约22 A，并且此表观运动与其他Tn亚基的运动相伴而生。这意味着通过绑定Ca（2 +），Tn亚基的重大结构重排发生。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号