在吸收紫外线的Rhodopsin中对不同潜在能量表面进行双光异构
Yusaku Hontani1, Matthias Broser2, Meike Luck2
1Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan, Amsterdam 1081 HV, The Netherlands.
与可见吸收类型不同,吸收紫外线的 rhodopsins 使用无质子的 Schiff 基. 这项研究揭示了吸收紫外线的丁激酶素1 (HKR1) 的完整激发和基态动态,包括独特的双异构反应.
科学领域:
- 摄影化学
- 生物物理
- 分子光谱学
背景情况:
- 吸收紫外线的罗多普辛对整个生命的紫外线视觉和感知至关重要.
- 它们与可见吸收的 rhodopsins 不同,因为它们与无质子的视网膜 Schiff 基结合.
- 吸收紫外线的 rhodopsins 的光反应动态仍然在很大程度上未被探索.
研究的目的:
- 阐明丁激酶罗多素1 (HKR1) 的紫外线形式的完整激发和基本状态动态.
- 了解素中紫外线诱导反应的独特光化学机制.
主要方法:
- 五秒刺激拉曼光谱法 (FSRS).
- 暂时的吸收光谱.
- 在五秒到百万秒的时间尺度上进行调查.
主要成果:
- 与可见吸收罗多普辛相比,发现了反向的能量水平排序 (S2状态是吸收紫外线的,S1状态是较低的和光学禁止的).
- 在激发状态下观察到由UV光刺激启动的新型双异构反应:C13C14 cis-trans异构 (<100 fs),然后在放松到基本状态时进行C15N16反同构异构 (4,8 ps).
- 检测到两个基态光产物 (全转换和13-cis/15-syn) 质子化形成蓝色吸收HKR1.
结论:
- 这项研究提供了对HKR1的紫外线诱导光化学的全面了解.
- 这些发现为动物和微生物罗多普辛的紫外线诱导光化学建立了基准.
- 这项研究揭示了控制紫外线传感和信号的基本机制.
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