Department of Chemistry, University of Southern California , Los Angeles, California 90089-0482, United States.
Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry , Moscow, Russia.
Chem Rev. 2017 Jan 25;117(2):758-795. doi: 10.1021/acs.chemrev.6b00238. Epub 2016 Oct 18.
Photoinduced reactions play an important role in the photocycle of fluorescent proteins from the green fluorescent protein (GFP) family. Among such processes are photoisomerization, photooxidation/photoreduction, breaking and making of covalent bonds, and excited-state proton transfer (ESPT). Many of these transformations are initiated by electron transfer (ET). The quantum yields of these processes vary significantly, from nearly 1 for ESPT to 10-10 for ET. Importantly, even when quantum yields are relatively small, at the conditions of repeated illumination the overall effect is significant. Depending on the task at hand, fluorescent protein photochemistry is regarded either as an asset facilitating new applications or as a nuisance leading to the loss of optical output. The phenomena arising due to phototransformations include (i) large Stokes shifts, (ii) photoconversions, photoactivation, and photoswitching, (iii) phototoxicity, (iv) blinking, (v) permanent bleaching, and (vi) formation of long-lived intermediates. The focus of this review is on the most recent experimental and theoretical work on photoinduced transformations in fluorescent proteins. We also provide an overview of the photophysics of fluorescent proteins, highlighting the interplay between photochemistry and other channels (fluorescence, radiationless relaxation, and intersystem crossing). The similarities and differences with photochemical processes in other biological systems and in dyes are also discussed.
光诱导反应在绿色荧光蛋白（GFP）家族的荧光蛋白的光循环中起着重要作用。这些过程包括光异构化、光氧化/光还原、共价键的断裂和形成，以及激发态质子转移（ESPT）。其中许多转化是由电子转移（ET）引发的。这些过程的量子产率差异很大，从近 1 的 ESPT 到 10-10 的 ET。重要的是，即使量子产率相对较小，在重复照明的条件下，整体效果也很显著。根据手头的任务，荧光蛋白光化学被视为促进新应用的资产，或导致光输出损失的麻烦。由于光转化而产生的现象包括 (i) 大斯托克斯位移，(ii) 光致变色、光激活和光开关，(iii) 光毒性，(iv) 闪烁，(v) 永久性漂白，和 (vi) 长寿命中间体的形成。本综述的重点是关于荧光蛋白中光诱导转化的最新实验和理论工作。我们还提供了荧光蛋白光物理的概述，强调了光化学与其他通道（荧光、无辐射弛豫和系间窜越）之间的相互作用。还讨论了与其他生物系统和染料中的光化学过程的相似性和差异性。
