Contribution of low-temperature single-molecule techniques to structural issues of pigment-protein complexes from photosynthetic purple bacteria.
Contribution of low-temperature single-molecule techniques to structural issues of pigment-protein complexes from photosynthetic purple bacteria.
复制标题
低温单分子技术对光合紫色细菌色素-蛋白质复合物结构问题的贡献。
DOI：
10.1098/rsif.2017.0680
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Löhner A
中科院分区：
文献类型：
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作者：
Löhner A
由于色素-蛋白质复合物中发色团的电子能量是由蛋白质的几何结构决定的，因此可以将获得的光谱信息与结构模型的预测进行比较。因此，单分子方法特别适合于阐明特定的、独特的光谱特征，这些光谱特征对于特定的模型结构是关键的，并且由于生物对象的异质性，在整体平均光谱中将不可观察到。在这篇简洁的评论中，我们以光合紫色细菌的捕光复合物为例说明了如何使用低温单分子光谱的结果来区分不同的结构模型。因此，低温方法提供了两个优点：（i）由于可忽略的光漂白，非常长的观察时间成为可能，更重要的是，（ii）在低温下，振动自由度被冻结，导致更清晰的光谱特征，进而更好地分辨光谱。
As the electronic energies of the chromophores in a pigment–protein complex are imposed by the geometrical structure of the protein, this allows the spectral information obtained to be compared with predictions derived from structural models. Thereby, the single-molecule approach is particularly suited for the elucidation of specific, distinctive spectral features that are key for a particular model structure, and that would not be observable in ensemble-averaged spectra due to the heterogeneity of the biological objects. In this concise review, we illustrate with the example of the light-harvesting complexes from photosynthetic purple bacteria how results from low-temperature single-molecule spectroscopy can be used to discriminate between different structural models. Thereby the low-temperature approach provides two advantages: (i) owing to the negligible photobleaching, very long observation times become possible, and more importantly, (ii) at cryogenic temperatures, vibrational degrees of freedom are frozen out, leading to sharper spectral features and in turn to better resolved spectra.