Dynamic Stokes shift in green fluorescent protein variants
Dynamic Stokes shift in green fluorescent protein variants
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DOI：
10.1073/pnas.0706185104
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发表时间：
2007-12-18
影响因子：
11.1
通讯作者：
Boxer, Steven G.
中科院分区：
文献类型：
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作者：
Abbyad, Paul;Childs, William;Boxer, Steven G.
在发色团的激发态周围的溶剂重组导致在激发态寿命期间发射向更长的波长移动。这种溶剂化反应在野生型绿色荧光蛋白中不存在，这被归因于生色团环境中的刚性，这是排除到基态的非辐射跃迁所必需的。荧光蛋白mPlum是通过红光选择定向进化得到的，我们利用时间分辨荧光研究了其进化过程中的动态斯托克斯位移。MPlum的远红光发射归因于在玻璃化转变以上的所有温度下都能观察到的皮秒溶剂化反应。这种依赖时间的排放变化在其进化祖先中没有观察到，这表明选择性压力已经产生了允许溶剂重组的生色团环境。相关荧光蛋白的进化途径和结构表明，靠近发色团的单个残基是溶剂化反应的主要原因。
Solvent reorganization around the excited state of a chromophore leads to an emission shift to longer wavelengths during the excited-state lifetime. This solvation response is absent in wildtype green fluorescent protein, and this has been attributed to rigidity in the chromophore's environment necessary to exclude nonradiative transitions to the ground state. The fluorescent protein mPlum was developed via directed evolution by selection for red emission, and we use time-resolved fluorescence to study the dynamic Stokes shift through its evolutionary history. The far-red emission of mPlum is attributed to a picosecond solvation response that is observed at all temperatures above the glass transition. This time-dependent shift in emission is not observed in its evolutionary ancestors, suggesting that selective pressure has produced a chromophore environment that allows solvent reorganization. The evolutionary pathway and structures of related fluorescent proteins suggest the role of a single residue in close proximity to the chromophore as the primary cause of the solvation response.