Selective photoinactivation of protein function through environment-sensitive switching of singlet oxygen generation by photosensitizer
Selective photoinactivation of protein function through environment-sensitive switching of singlet oxygen generation by photosensitizer
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DOI：
10.1073/pnas.0611717105
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发表时间：
2008-01
期刊：
影响因子：
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通讯作者：
T. Yogo;Y. Urano;A. Mizushima;Hisato Sunahara;Takanari Inoue;K. Hirose;M. Iino;K. Kikuchi;
中科院分区：
文献类型：
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作者：
T. Yogo;Y. Urano;A. Mizushima;Hisato Sunahara;Takanari Inoue;K. Hirose;M. Iino;K. Kikuchi;
生色团辅助的光灭活技术是一种很有前景的技术，可以在活细胞中以高空间和时间分辨率灭活选定的蛋白质，但由于缺乏一种方法来防止由于光敏剂产生的活性氧物种而导致的细胞非特异性光损伤，其应用受到了限制。在这里，我们提出了一种光敏剂的设计策略，该光敏剂具有环境敏感的关闭/开启开关来产生单线态氧(1O2)，通过与靶结合来开启，以提高蛋白质光失活的特异性。在非结合状态下，1O2的产生被光诱导电子转移所猝灭，而在特定结合后，在靶蛋白提供的疏水环境中可以产生1O2。1，4，5-三磷酸肌醇受体被认为在配体结合部位周围有一个疏水口袋，它被环境敏感型光敏剂结合的三磷酸肌醇受体配体特异性地灭活，尽管有光照射，但靶细胞胞浆中不产生1O2，这表明环境敏感型光敏剂具有高分辨率控制细胞内活性氧产生的潜力。
Chromophore-assisted light inactivation is a promising technique to inactivate selected proteins with high spatial and temporal resolution in living cells, but its use has been limited because of the lack of a methodology to prevent nonspecific photodamage in the cell owing to reactive oxygen species generated by the photosensitizer. Here we present a design strategy for photosensitizers with an environment-sensitive off/on switch for singlet oxygen (1O2) generation, which is switched on by binding to the target, to improve the specificity of protein photoinactivation. 1O2 generation in the unbound state is quenched by photoinduced electron transfer, whereas 1O2 generation can occur in the hydrophobic environment provided by the target protein, after specific binding. Inositol 1,4,5-trisphosphate receptor, which has been suggested to have a hydrophobic pocket around the ligand binding site, was specifically inactivated by an environment-sensitive photosensitizer-conjugated inositol 1,4,5-trisphosphate receptor ligand without 1O2 generation in the cytosol of the target cells, despite light illumination, demonstrating the potential of environment-sensitive photosensitizers to allow high-resolution control of generation of reactive oxygen species in the cell.