微秒光诱导的质子转移到蓝光传感器植物中的黄素密码色
Thomas Langenbacher1, Dominik Immeln, Bernhard Dick
1Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93053 Regensburg, Germany.
Journal of the American Chemical Society
|September 17, 2009
概括
植物加密染色体,蓝光传感器,经历快速光降解. 确定了一种新的微秒质子转移步骤,与动物的加密色素和光聚酶不同.
科学领域:
- 植物生物学 植物生物学
- 光感受器研究研究
- 生物化学 生物化学
背景情况:
- 植物加密染色体是蓝光光受体,对植物生长,日常节律和潜在的磁感应至关重要.
- 它们与DNA修复光解酶具有结构上的相似性,并使用黄胺二核酸 (FAD) 作为染色体.
- 光吸收触发了flavin光降解,产生了一个信号flavin中性基.
研究的目的:
- 为了研究加密色光还原超快的动态,超出了毫秒时间尺度.
- 为了阐明藻类加密染色体中电子和质子转移事件的时间序列.
- 为了比较光还原机制与动物的加密染色体和光解酶.
主要方法:
- 时间分辨率吸收光谱利用串行摄像机设置.
- 监测 375-750 nm 范围内的光谱变化.
- 分析光引起的吸收变化,以确定反应动力学.
主要成果:
- 从托到黄的电子转移发生在100 ns内,形成一个黄离子基.
- 一个具有1.7微秒时间常数的质子转移步骤产生了flavin中性基.
- 黄素基和酸基的衰变发生在200微秒,毫秒和秒的时间内.
结论:
- 观察到的微秒质子转移是植物/藻类加密染色体的独特特征,并未在动物对应物或光散酶中观察到.
- 电子和质子转移的明显时间分离是弗拉文光受体研究中的新发现.
- 反应动力学表明,质子捐赠者与N5素没有密切的结距离,这促使进一步调查潜在的捐赠者和托三合一的作用.
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