FTIR study of the photoinduced processes of plant phytochrome phyA using isotope-labeled bilins and density functional theory calculations.
FTIR study of the photoinduced processes of plant phytochrome phyA using isotope-labeled bilins and density functional theory calculations.
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使用同位素标记的胆碱和密度泛函理论计算对植物光敏色素 phyA 的光诱导过程进行 FTIR 研究。
DOI：
10.1529/biophysj.108.131441
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发表时间：
2008
影响因子：
3.4
通讯作者：
F. Siebert
中科院分区：
文献类型：
--
作者：
P. Schwinté;H. Foerstendorf;Z. Hussain;W. Gärtner;M. Mroginski;P. Hildebrandt;F. Siebert
利用傅里叶变换红外光谱分析了植物光敏色素phyA的母态Pr和Pfr以及各自的光产物lumi-R和lumi-F的发色团结构。光谱是从与均匀或选择性同位素标记的植物色素蛋白和藻蓝蛋白组装的phyA加合物获得的。实验光谱的解释基于密度泛函理论计算的发色团模型的光谱。四吡咯的整体 (13)C 标记可以区分傅里叶变换红外差异光谱中的发色团和蛋白质带。所有红外差异光谱均显示出显着的差异带，该差异带可归因于拉伸模式，其中内吡咯环之间的次甲基桥贡献很大（B-C拉伸）。由于模式耦合，该模式的频率和同位素位移表明 Pr 生色团可能采用扭曲的 ZZZssa 或 ZZZasa 几何结构，具有扭曲的 A-B 次甲基桥。向lumi-R的转变仅与酰胺I带的微小变化相关，这表明在C-D次甲基桥异构化位点期间蛋白质结构变化有限。主要的蛋白质结构变化发生在转变为 Pfr 时，其中发色团采用 ZZEssa 或 ZZEasa 样状态。此外，与蛋白质的特异性相互作用改变了 B-C 次甲基桥的结构，正如从相应拉伸模式的大幅下调得出的结论。这些相互作用在 lumi-F (ZZE-->ZZZ) 光反应过程中被消除，仅涉及很小的蛋白质结构变化。
Fourier transform infrared spectroscopy was used to analyze the chromophore structure in the parent states Pr and Pfr of plant phytochrome phyA and the respective photoproducts lumi-R and lumi-F. The spectra were obtained from phyA adducts assembled with either uniformly or selectively isotope-labeled phytochromobilin and phycocyanobilin. The interpretation of the experimental spectra is based on the spectra of chromophore models calculated by density functional theory. Global (13)C-labeling of the tetrapyrrole allows for the discrimination between chromophore and protein bands in the Fourier transform infrared difference spectra. All infrared difference spectra display a prominent difference band attributable to a stretching mode with large contributions from the methine bridge between the inner pyrrole rings (B-C stretching). Due to mode coupling, frequencies and isotopic shifts of this mode suggest that the Pr chromophore may adopt a distorted ZZZssa or ZZZasa geometry with a twisted A-B methine bridge. The transition to lumi-R is associated with only minor changes of the amide I bands indicating limited protein structural changes during the isomerization site of the C-D methine bridge. Major protein structural changes occur upon the transition to Pfr in which the chromophore adopts a ZZEssa or ZZEasa-like state. In addition, specific interactions with the protein alter the structure of the B-C methine bridge as concluded from the substantial downshift of the respective stretching mode. These interactions are removed during the photoreaction to lumi-F (ZZE-->ZZZ), which involves only small protein structural changes.
影响因子：
56.9
作者：
Fankhauser, C;Yeh, KC;Chory, J
通讯作者：
Chory, J
DOI：
10.1073/pnas.95.23.13976
发表时间：
1998-11-10
影响因子：
11.1
作者：
Yeh, KC;Lagarias, JC
通讯作者：
Lagarias, JC