在贝斯特罗多普辛光反应的早期阶段,多个视网膜异构
Spyridon Kaziannis1,2, Matthias Broser3, Ivo H M van Stokkum4
1The Extreme Light Infrastructure ERIC, Dolní Břežany 252 41, Czech Republic.
概括
贝斯特罗多普辛经历复杂的光诱导异构化. 这项研究揭示了Phaeocystis antarctica中11-cis和13-cis视网膜Schiff-base配置之间的广泛的基态切换.
科学领域:
- 结构生物学是结构生物学.
- 摄影化学的使用.
- 生物物理学的生物物理.
背景情况:
- 贝斯特罗多普辛是光调节的离子通道,具有双重罗多普辛和贝斯特罗芬域.
- 这些通道对于各种生物体的细胞功能至关重要,对光刺激做出反应.
研究的目的:
- 为了研究费奥西斯蒂斯南极洲最佳罗多普辛中罗多普辛合域的异构化动态.
- 为了阐明视网膜Schiff-base (RSB) 染色体在照明时的结构变化.
主要方法:
- 对贝斯特罗多普辛的光诱导变化的光谱分析.
- 时间解析的研究,以追踪光产品的演变.
主要成果:
- 全透射RSB (λmax 661 nm) 的照明导致P682的形成,P682是扭曲的11-cis和13-cis RSB的混合物,在1.4 psi范围内.
- 在500ps后,P682演变为P673 (高度扭曲的13-cis RSB),随后在1.2μs后与P595 (11-cis RSB) 平衡.
- 进一步放松后在1.0毫秒内产生P560 (48微秒) 和转移稳定的P540 (11-cis RSB),表明了广泛的基态异构.
结论:
- 广泛的RSB异构切换发生在ps到μs时间尺度上,由形交叉驱动,并由蛋白质构造变化促进.
- 一个狭窄的形状景观允许在紧张的11-cis和13-cis RSB中间体之间进行热切换.
- 蛋白质放松最终导致P540光产品中稳定的11-cis异构体配置.
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