Resonance Raman spectra of the acidified and deionized forms of bacteriorhodopsin.
Resonance Raman spectra of the acidified and deionized forms of bacteriorhodopsin.
复制标题
酸化和去离子形式的细菌视紫红质的共振拉曼光谱。
DOI：
10.1016/s0006-3495(85)83899-6
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发表时间：
1985
影响因子：
3.4
通讯作者：
Mathies,RA
中科院分区：
文献类型：
--
作者：
Smith,SO;Mathies,RA
光适应性细菌视紫红质（BR）的568 nm吸收带在pH 2时移到605 nm，形成BR 605 A，在pH 0时移回565 nm，形成BR 565 A。我们已经获得了共振拉曼光谱BR 605 A和BR 565 A使用紫膜样品已悬浮在旋转拉曼池与聚丙烯酰胺凝胶。紫膜（BR 605 D）在去离子溶液中的拉曼光谱也被获得。BR 605 A和BR 605 D的光谱非常相似，并且它们与暗适应BR的拉曼光谱密切对应，暗适应BR包含13-顺式和全反式视网膜质子化席夫碱发色团的近似相等的混合物。这表明BR 605 A和BR 605 D不是同质的分子种类，而是含有具有13-顺式和全反式视黄醇异构体的色素分子的混合物。BR 565 A的拉曼光谱与光适应BR的拉曼光谱几乎相同，表明BR 565 A含有全反式质子化希夫碱发色团。这些数据提供了可能的结构变化，可以调用来解释在酸和去离子物种诱导的光谱位移的约束。
The 568-nm absorption band of light-adapted bacteriorhodopsin (BR) shifts to 605 nm at pH 2, forming BR605A, and it shifts back to 565 nm at pH 0, forming BR565A. We have obtained resonance Raman spectra of BR605A and BR565A using purple membrane samples that have been suspended in a rotating Raman cell with a polyacrylamide gel. Raman spectra were also obtained of purple membrane in deionized solutions (BR605D). The spectra of BR605A and BR605D are very similar, and they correspond closely with the Raman spectrum of dark-adapted BR, which contains an approximately equal mixture of 13-cis and all-trans retinal protonated Schiff-base chromophores. This shows that BR605A and BR605D are not homogeneous molecular species but contain a mixture of pigment molecules with both 13-cis and all-trans retinal isomers. The Raman spectrum of BR565A is nearly identical to that of light-adapted BR, demonstrating that BR565A contains an all-trans protonated Schiff-base chromophore. These data provide constraints on the possible structural changes that can be invoked to explain the spectral shifts induced in the acid and deionized species.