第一个原则 难以捉摸的I光状态的表征和视网膜质子 Schiff 基的结构演变 在bacteriorhodopsin
Jimmy K Yu1,2,3, Ruibin Liang1,3, Fang Liu4
1Department of Chemistry and The PULSE Institute , Stanford University , Stanford , California 94305 , United States.
Journal of the American Chemical Society
|October 18, 2019
概括
细菌素 (bR) 使用光能进行质子. 新的模拟显示了其激发状态的动态,包括光状态和屏障,澄清了超快光反应机制.
科学领域:
- 生物物理
- 计算化学
- 摄影科学
背景情况:
- 细菌原素 (bR) 是一种模型光活性蛋白,对于将光能转化为细胞工作至关重要.
- 它的染色体,视网膜质子化希夫基 (RPSB),在光子吸收时异构,驱动质子.
- 之前的研究对bR激发状态动态的细节,包括I状态和反应机制,是不确定的.
研究的目的:
- 模拟细菌素中超快光反应的非adiabatic动态.
- 描述I光状态和激发状态屏障.
- 阐明RPSB对电离子集群在光异构化过程中的作用.
主要方法:
- 一开始多次产卵 (AIMS) 模拟.
- 旋转受限组合Kohn-Sham (REKS) 理论
- 超快的光反应动力学模拟.
主要成果:
- 激发状态动力学发生在三个阶段:弗兰克-康登放松,I状态的停留时间,以及扭转演变到形交叉点.
- I光状态完全具有特征,具有没有扭曲的,链条长度反转的RPSB.
- 一个小的兴奋状态障碍被确定,阻碍了直接进化到形交叉点.
- 光异构化减弱了RPSB-对子集群相互作用,但不需要键裂变.
结论:
- 这项研究提供了细致的细节细节细节细节细节细节细节细节细节细节细节细节细节细节细节细节细节细节.
- 已识别的I状态和激发状态屏障完善了我们对光能转换的理解.
- 模拟结果提供了RPSB与其环境在光异构化过程中的相互作用的见解.
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