...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical chemistry chemical physics: PCCP >Excited state dynamics and catalytic mechanism of the light-driven enzyme protochlorophyllide oxidoreductase
【24h】

Excited state dynamics and catalytic mechanism of the light-driven enzyme protochlorophyllide oxidoreductase

机译：光驱动酶原叶绿素内酯氧化还原酶的激发态动力学和催化机理

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

The reduction of protochlorophyllide (Pchlide) to chlorophyllide, catalysed by the enzyme protochlorophyllide oxidoreductase (POR), is the penultimate step in the chlorophyll biosynthetic pathway and is a key light-driven reaction that triggers a profound transformation in plant development. As POR is light-activated it can provide new information on the way in which light energy can be harnessed to power enzyme reactions. Consequently, POR presents a unique opportunity to study catalysis at low temperatures and on ultrafast timescales, which are not usually accessible for the majority of enzymes. Recent advances in our understanding of the catalytic mechanism of POR illustrate why it is an important model for studying enzyme catalysis and reaction dynamics. The reaction involves the addition of one hydride and one proton, and catalysis is initiated by the absorption of light by the Pchlide substrate. As the reaction involves the Pchlide excited state, a variety of ultrafast spectroscopic measurements have shown that significant parts of the reaction occur on the picosecond timescale. A number of excited state Pchlide species, including an intramolecular charge transfer complex and a hydrogen bonded intermediate, are proposed to be required for the subsequent hydride and proton transfers, which occur on the microsecond timescale. Herein, we review spectroscopic investigations, with a particular focus on time-resolved transient absorption and fluorescence experiments that have been used to study the excited state dynamics and catalytic mechanism of POR.
机译：原叶绿素氧化还原酶（POR）催化将原叶绿素（Pchlide）还原为叶绿素，是叶绿素生物合成途径中的倒数第二个步骤，并且是引发植物发展深刻转化的关键光驱动反应。由于POR是光激活的，因此可以提供有关利用光能促进酶反应的方式的新信息。因此，POR提供了一个独特的机会来研究在低温和超快速度范围内的催化作用，而大多数酶通常无法获得这种作用。我们对POR催化机理的了解的最新进展说明了为什么POR是研究酶催化和反应动力学的重要模型。该反应包括添加一种氢化物和一种质子，并且通过Pchlide底物吸收光来引发催化作用。由于反应涉及Pchlide激发态，因此各种超快光谱测量表明，反应的重要部分在皮秒级的时间范围内发生。提出许多激发态的Pchlide物质，包括分子内的电荷转移络合物和氢键合的中间体，对于随后的氢化物和质子转移是必需的，这些转移发生在微秒级。本文中，我们回顾了光谱学研究，特别关注时间分辨的瞬态吸收和荧光实验，该实验已用于研究POR的激发态动力学和催化机理。

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