Department of Life Sciences, Imperial College London, London, United Kingdom; email:
Department of Physics, Northeastern University, Boston, Massachusetts, USA; email:
Annu Rev Phys Chem. 2023 Apr 24;74:123-144. doi: 10.1146/annurev-physchem-091422-102619. Epub 2023 Jan 25.
The photoacid dynamics of fluorescent proteins include both electronic excited- and ground-state mechanisms of proton transfer. The associated characteristic timescales of these reactions range over many orders of magnitude, and the tunneling, barrier crossing, and relevant thermodynamics have in certain cases been linked to coherent nuclear motion. We review the literature and summarize the experiments and theory that demonstrate proton tunneling in the electronic ground state of the green fluorescent protein (GFP). We also discuss the excited-state proton-transfer reaction of GFP that takes place on the picosecond timescale. Although this reaction has been investigated using several vibrational spectroscopic methods, the interpretation remains unsettled. We discuss recent advances as well as remaining questions, in particular those related to the vibrational mode couplings that involve low-frequency modulations of chromophore vibrations on the timescale of proton transfer.
荧光蛋白的光酸动力学包括质子转移的电子激发态和基态机制。这些反应的相关特征时间尺度跨越了多个数量级，并且在某些情况下，隧道、势垒穿越和相关热力学已经与相干核运动相关联。我们回顾了文献，并总结了证明绿色荧光蛋白 (GFP) 电子基态中质子隧道的实验和理论。我们还讨论了 GFP 的激发态质子转移反应，该反应发生在皮秒时间尺度上。尽管已经使用几种振动光谱方法研究了该反应，但解释仍然不确定。我们讨论了最近的进展以及仍然存在的问题，特别是与涉及发色团振动的低频调制的质子转移时间尺度上的振动模式耦合相关的问题。
