Primary Role of the Chromophore Bond Length Alternation in Reversible Photoconversion of Red Fluorescence Proteins
Primary Role of the Chromophore Bond Length Alternation in Reversible Photoconversion of Red Fluorescence Proteins
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DOI：
10.1038/srep00688
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发表时间：
2012-09-24
影响因子：
4.6
通讯作者：
Rebane, Aleksander
中科院分区：
文献类型：
--
作者：
Drobizhev, Mikhail;Hughes, Thomas E.;Rebane, Aleksander
荧光蛋白的快速光漂白会限制其在成像应用中的使用。潜在的动力学是多指数的，强烈依赖于当地的发色团环境。第一个可逆的步骤可能是由于围绕发色团中桥接苯酚和咪唑啉酮基团的两个环外C-C键之一的旋转。然而，目前尚不清楚蛋白质环境如何控制这种运动-通过空间位阻或通过静电相互作用调节发色团的电子结构。在这里，我们研究了13个红色荧光蛋白（RFPs）的光漂白动力学的第一步与不同的发色团的环境，并表明，相关速率强烈相关的两个桥键的键长交替（BLA）。BLA的符号似乎确定哪个旋转被激活。我们的研究结果提出了实验证据的RFP发色团的构象动力学中的电子效应的优势。
Rapid photobleaching of fluorescent proteins can limit their use in imaging applications. The underlying kinetics is multi-exponential and strongly depends on the local chromophore environment. The first, reversible, step may be attributed to a rotation around one of the two exocyclic C-C bonds bridging phenol and imidazolinone groups in the chromophore. However it is not clear how the protein environment controls this motion - either by steric hindrances or by modulating the electronic structure of the chromophore through electrostatic interactions. Here we study the first step of the photobleaching kinetics in 13 red fluorescent proteins (RFPs) with different chromophore environment and show that the associated rate strongly correlates with the bond length alternation (BLA) of the two bridge bonds. The sign of the BLA appears to determine which rotation is activated. Our results present experimental evidence for the dominance of electronic effects in the conformational dynamics of the RFP chromophore.