Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C, Denmark.
Phys Chem Chem Phys. 2009 Nov 21;11(43):9996-10002. doi: 10.1039/b914276b. Epub 2009 Sep 17.
We report on gas-phase experimental and theoretical studies on the neutral form of the green-fluorescent protein (GFP) chromophore using six different models, each carrying a spectator positive charge. Theoretical studies were carried out to quantify the effect of the spectator charge on the absorption maximum of the true neutral. The study also includes models having the possibility of forming intra-molecular hydrogen bonds, and their effect on the absorption profile is analyzed. The charge redistribution caused by a strong intra-molecular hydrogen bond was found to give rise to a red shift in going from non-hydrogen bonded to hydrogen bonded models. For the non-hydrogen bonded models, the length of the side chain as well as the group carrying the spectator charge, was varied to explore the possibility of shifts in absorption maximum due to these variations. No shifts were observed. The implications of these results in tuning the absorption maximum of the neutral form of the GFP chromophores are discussed.
我们报告了使用六种不同模型的气相实验和理论研究，这些模型都带有一个旁观正电荷。理论研究旨在量化旁观电荷对真中性的吸收最大值的影响。该研究还包括有可能形成分子内氢键的模型，并分析了它们对吸收曲线的影响。研究发现，由于强分子内氢键引起的电荷再分配导致从非氢键到氢键模型的吸收峰红移。对于非氢键模型，改变侧链的长度以及带有旁观电荷的基团，以探索由于这些变化导致吸收最大值偏移的可能性。没有观察到偏移。讨论了这些结果在调节 GFP 发色团中性形式的吸收最大值方面的意义。
