Fluorescent derivatives of the GFP chromophore give a new insight into the GFP fluorescence process
Fluorescent derivatives of the GFP chromophore give a new insight into the GFP fluorescence process
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DOI：
10.1016/s0006-3495(03)74612-8
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发表时间：
2003-09-01
影响因子：
3.4
通讯作者：
Pigault, C
中科院分区：
文献类型：
--
作者：
Follenius-Wund, A;Bourotte, M;Pigault, C
测定了源自绿色荧光蛋白的咪唑啉酮发色团的合成化合物的光物理性质。引入各种吸电子或供电子取代基来模拟蛋白质中发色团环境的影响。二恶烷和甘油中的吸收和发射光谱以及荧光量子产率高度依赖于取代基的电子性质。我们提出了一种动力学方案，该方案考虑了受激分子的温度依赖性扭曲。如果活化能较低，分子通常会经历激发态分子内扭曲，通过避免 S-1 和 S-0 能量表面之间的交叉导致其达到基态。对于高活化能，化合物内的扭转运动受到限制，基态恢复将优先通过荧光发射发生。荧光量子产率和计算的扭转活化能之间的良好相关性表明上述避免的交叉是这些化合物中主要的非辐射失活通道。最后，我们对绿色荧光蛋白及其一些突变体中的发色团的结果进行了讨论。
The photophysical properties of synthetic compounds derived from the imidazolidinone chromophore of the green fluorescent protein were determined. Various electron-withdrawing or electron-donating substituents were introduced to mimic the effect of the chromophore surroundings in the protein. The absorption and emission spectra as well as the fluorescence quantum yields in dioxane and glycerol were shown to be highly dependent on the electronic properties of the substituents. We propose a kinetic scheme that takes into account the temperature-dependent twisting of the excited molecule. If the activation energy is low, the molecule most often undergoes an excited-state intramolecular twisting that leads it to the ground state through an avoided crossing between the S-1 and S-0 energy surfaces. For a high activation energy, the torsional motion within the compounds is limited and the ground-state recovery will occur preferentially by fluorescence emission. The excellent correlation between the fluorescence quantum yields and the calculated activation energies to torsion points to the above-mentioned avoided crossing as the main nonradiative deactivation channel in these compounds. Finally, our results are discussed with regard to the chromophore in green fluorescent protein and some of its mutants.