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Femtosecond Spectroscopy of Primary Processes of Photoisomerizations in Rhodopsin and Retinoid Proteins

视紫红质和类维生素A蛋白光异构化初级过程的飞秒光谱

基本信息

批准号：
02452299
负责人：
KOBAYASHI Takayoshi
金额：
$ 0.77万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

项目摘要

The visual systems with rhodopsin and other retinoid proteins with retinal have high sensitivity, low noise, and wide dynamic range, In this research, the primary processes of photoisomerization of rhodopsins have been investigated in femtosecond to picosecond time region.The time-resolved spectroscopy apparatus with using tunable femtosecond light pulses in the spectral region of 500-570nm region was constructed, The tunable pulses are obtained by using two-stage dye amplifiers of wavelengthselected femtosecond continuum generated by self-phase modulation. The experiment has improves the data dramatically in time resolution in comparison with previous works. The time resolution of the system is about 300 fs.The detailed mechanism of the excited state dynamics of octopus rhodopsin is clarified. The lifetime of the excited state absorption in 700 nm is about 140 fs. Primerhodopsin (Prime) is generated within 400 fs and the absorption spectrum resembles the spectrum of Bathorhodopsin (Batho), Prime is more likely unthermalized state of Batho, Another state is observed as a gain in the 800 nm region with 2-4 ps lifetime.An analog of bacteriorhodopsin (BR), 14-fluorobacteriorhodopsin (14-F-BR), was also investigated to clarify the relationship between the electric structure and the dynamics of ultrafast structure changes. The feature of the absorbance changes are quite similar to those of BR. The fact that an introduction of fluorine atom does not affect the primary relaxation dynamics indicates that the electronic structure is not an important factor for the dynamics of trans-cis isomerization.

视紫红质和其他视网膜类视黄醇蛋白的视觉系统具有高灵敏度、低噪声和宽动态范围的特点，本研究在飞秒至皮秒时间范围内研究了视紫红质光异构化的初级过程。构建了在500-570nm光谱范围内使用可调谐飞秒光脉冲的时间分辨光谱仪，可调谐脉冲是通过使用由自相位调制产生的波长选择飞秒连续谱的两级染料放大器获得的。与之前的工作相比，该实验在时间分辨率上显着提高了数据。该系统的时间分辨率约为300 fs。阐明了章鱼视紫红质激发态动力学的详细机制。 700 nm 激发态吸收的寿命约为 140 fs。 Primerhodopsin (Prime) 在 400 fs 内生成，吸收光谱类似于 Bathorhodopsin (Batho) 的光谱，Prime 更可能是 Batho 的非热化状态，观察到另一种状态为 800 nm 区域的增益，寿命为 2-4 ps。细菌视紫红质 (BR) 的类似物 14-氟细菌视紫红质 (14-F-BR) 也被观察到研究旨在阐明电结构与超快结构变化动力学之间的关系。吸光度变化特征与BR非常相似。氟原子的引入不影响初级弛豫动力学这一事实表明电子结构并不是反式-顺式异构化动力学的重要因素。