Max-Planck Institute for Medical Research, Jahnstraße 29, 69120 Heidelberg, Germany.
Phys Chem Chem Phys. 2020 Apr 29;22(16):8535-8544. doi: 10.1039/d0cp00814a.
Photoinduced double-bond isomerisation of the chromophore of photoactive yellow protein (PYP) is highly sensitive to chromophore-protein interactions. On the basis of high-level ab initio calculations, we scrutinise the effect of hydrogen bonds on the photophysical and photochemical properties of the chromophore. We identify four resonance structures - two closed-shell and two biradicaloid - that elucidate the electronic structure of the ground and first excited states involved in the isomerisation process. Changing the relative energies of the resonance structures by hydrogen-bonding interactions tunes all photochemical properties of the chromophore in an interdependent manner. Our study sheds new light on the role of the chromophore electronic structure in tuning in photosensors and fluorescent proteins.
光致变色双键异构化光激活黄色蛋白（PYP）的生色团对生色团-蛋白质相互作用非常敏感。基于高级从头算计算，我们仔细研究了氢键对生色团光物理和光化学性质的影响。我们确定了四个共振结构 - 两个闭壳层和两个双自由基 - 阐明了参与异构化过程的基态和第一激发态的电子结构。通过氢键相互作用改变共振结构的相对能量以相互依赖的方式调谐生色团的所有光化学性质。我们的研究揭示了生色团电子结构在调节光传感器和荧光蛋白中的作用。
