长距离的质子转移与一个突破的背后多普辛活跃部位
Prasad Phatak1, Jan S Frähmcke, Marius Wanko
1Institute of Physical and Theoretical Chemistry, TU Braunschweig, D-38106 Braunschweig, Germany.
Journal of the American Chemical Society
|May 2, 2009
概括
细菌原素质子转移涉及一个短暂的状态,其中Asp212被质子化,促进质子运动. 这项研究使用了计算方法来探索Halobacterium salinarium中的这种机制.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 计算生物物理学的计算生物物理学
背景情况:
- 细菌是Halobacterium salinarium中的一个光驱动的质子.
- 质子运输涉及视网膜异质化和形状变化.
- 长距离质子转移机制,特别是在O状态期间,仍然不清楚.
研究的目的:
- 为了研究一个涉及Asp212质子化的过渡性中间状态的作用.
- 阐明从Asp85到质子释放组的长距离质子转移机制.
- 评估Asp212对Asp85.5的去质子化的贡献.
主要方法:
- 混合量子力学/分子力学 (QM/MM) 质子转移计算.
- 利用了各种蛋白质结构,视网膜几何形状和活跃站点水配置.
- 经过验证的结构模型使用紫外线激发能和C=O振动频率.
主要成果:
- 计算表明,在质子转移过程中采集了具有质子Asp212的短暂[O]符合器.
- 这种质子化Asp212可能参与Asp85.5的去质子化.
- 最初的质子转移状态 (O) 涉及扭曲的视网膜和至少三个水分子.
结论:
- Asp212的短暂质子化是bacteriorhodopsin的质子转移途径中的一个合理的中间体.
- 这些发现为穿过膜的质子转移的分子机制提供了洞察力.
- 计算建模对于理解复杂的生物分子过程至关重要,例如质子.
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