Observing Vibrational Energy Flow in a Protein with the Spatial Resolution of a Single Amino Acid Residue
Observing Vibrational Energy Flow in a Protein with the Spatial Resolution of a Single Amino Acid Residue
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DOI：
10.1021/jz501882h
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发表时间：
2014-09-18
影响因子：
5.7
通讯作者：
Mizutani, Yasuhisa
中科院分区：
文献类型：
--
作者：
Fujii, Naoki;Mizuno, Misao;Mizutani, Yasuhisa
物理化学的挑战之一是从微观角度理解能量如何在凝聚相中流动。为了解决这个问题，需要分子尺度的空间分辨信息，但由于实验困难而一直缺乏。我们成功地在一个蛋白质的振动能量流的实时映射与空间分辨率的单个氨基酸残基的时间分辨共振拉曼光谱和定点单色氨酸诱变相结合。反斯托克斯拉曼强度的色氨酸残基在不同的网站表现出不同的时间演变，反映了传播的血红素基团释放的能量。经典的热传递模型无法重现整个实验数据集，这表明我们需要分子水平的描述来解释蛋白质中的能量流。系统地应用我们的一般方法，以不同的结构基序的蛋白质，可以提供一个大大增加的了解蛋白质中的能量流。
One of the challenges in physical chemistry has been understanding how energy flows in a condensed phase from the microscopic viewpoint. To address this, space-resolved information at the molecular scale is required but has been lacking due to experimental difficulties. We succeeded in the real-time mapping of the vibrational energy flow in a protein with the spatial resolution of a single amino acid residue by combining time-resolved resonance Raman spectroscopy and site-directed single-Trp mutagenesis. Anti-Stokes Raman intensities of the Trp residues at different sites exhibited different temporal evolutions, reflecting propagation of the energy released by the heme group. A classical heat transport model was not able to reproduce the entire experimental data set, showing that we need a molecular-level description to explain the energy flow in a protein. The systematic application of our general methodology to proteins with different structural motifs may provide a greatly increased understanding of the energy flow in proteins.