...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >THE PHOTORECEPTOR SENSORY RHODOPSIN I AS A TWO-PHOTON DRIVEN PROTON PUMP
【24h】

THE PHOTORECEPTOR SENSORY RHODOPSIN I AS A TWO-PHOTON DRIVEN PROTON PUMP

机译：光电感受器视紫红质I作为两光子驱动的质子泵

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

Proton translocation experiments with intact cells of Halobacterium salinarium overproducing sensory rhodopsin I (SRI) revealed transport activity of SRI in a two-photon process, The vectoriality of proton translocation depends on pH, being outwardly directed above, and inwardly directed below, pH 5.7. Activation of the transport cycle requires excitation of the initial dark state of SRI, SRI(590), to form the intermediate SRI(380). Action spectra identify the photocycle intermediates SRI(380) and SRI(520) as the two photochemically reactive species in the outwardly directed transport process. As shown by flash photolysis experiments, SRI(520) undergoes a so-far unknown photochemical reaction to SRI(380) With a half-time of <200 mu s. Mutation of SRI residue Asp-76, the residue which is equivalent to the proton acceptor Asp-85 in bacteriorhodopsin, to asparagine leads to inactivation of proton translocation. This demonstrates that the underlying mechanisms of proton transport in both retinal proteins share similar features, However, SRI is to our knowledge the first case where photochemical reactions between two thermally unstable photoproducts of a retinal protein constitute a catalytic ion transport cycle. [References: 38]
机译：用过量生产感官视紫红质I（SRI）的盐杆菌盐藻完整细胞进行质子易位实验，显示了SRI在两个光子过程中的运输活性。质子易位的矢量性取决于pH值，pH值从上向外，向内指向pH 5.7以下。激活运输周期需要激发SRI的初始黑暗状态SRI（590），以形成中间SRI（380）。动作光谱将光循环中间体SRI（380）和SRI（520）确定为向外定向传输过程中的两个光化学反应性物质。如快速光解实验所示，SRI（520）对SRI（380）进行了迄今未知的光化学反应，半衰期小于200μs。 SRI残基Asp-76（相当于细菌视紫红质中的质子受体Asp-85的残基）突变为天冬酰胺会导致质子易位失活。这证明了两种视网膜蛋白中质子转运的基本机理具有相似的特征。然而，据我们所知，SRI是第一种情况，其中两种热不稳定的视网膜蛋白光产物之间的光化学反应构成催化离子转运周期。 [参考：38]

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