在主要的光采集复合体LHCIIII中,氨酸的超快兴奋状态动态
Laura Pedraza-González1, Davide Accomasso1, Lorenzo Cupellini1
1Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124, Pisa, Italy.
概括
蛋白质环境通过改变它们的电子结构和几何来调整光收获复合II (LHCII) 中的蛋白色素. 在LHCII中研究了超快的动态和蛋白之间的能量转移,但在超快的时间尺度上没有显著的能量转移.
科学领域:
- 光合作用研究研究光合作用.
- 植物生物化学 植物生物化学
- 计算生物物理学的计算生物物理.
背景情况:
- 胡卜素颜料,如蛋白,对于植物的光收获复合体至关重要.
- 它们的功能多功能性源于可调节的电子结构和受蛋白质环境影响的灵活几何形状.
研究的目的:
- 研究植物光采集综合体II (LHCII) 中的L1和L2位点如何调节嵌入式素的电子结构和超快动态.
- 为了探索这两种黄蛋白分子之间的能量转移机制.
主要方法:
- 混合分子动力学 (MD) 和量子力学/分子力学 (QM/MM) 的计算.
- 表面跳跃模拟以分析超快速动态.
- 福斯特理论和激发性表面跳跃来研究能量转移.
主要成果:
- 在L1和L2位点的氨酸表现出不同的构造,L2倾向于更平面的几何形状.
- 这种L2的平面性导致偏移的增加和较低的激发能量,解释了实验红移.
- 两种黄素的超快动态都显示出类似的衰变,从明亮到黑暗状态在50 fs内.
- 使用两个不同的理论方法,在超快的时间尺度上没有检测到蛋白之间显著的能量转移.
结论:
- 蛋白质环境显著调整LHCII内的黄蛋白特性,影响其电子结构和光谱特征.
- 尽管结构上有差异,但LHCII中的黄素表现出类似的超快激发状态动态.
- 在超快的时间尺度上,LHCII中氨酸之间的能量转移是可以忽略不计的.
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