Clément Jean-Emmanuel, Leray Aymeric, Bouhelier Alexandre, Finot Eric
Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS, Université Bourgogne Franche-Comté, 21000 Dijon, France.
Phys Chem Chem Phys. 2016 Dec 21;19(1):458-466. doi: 10.1039/c6cp06667d.
In this contribution, we provide new insights on the temporal fluctuations of surface enhanced Raman spectra (SERS) of large single molecules such as proteins. Because they can only fit partly into small active volume, SERS analysis is referred to spectral pointillism where only protein subdomains are shined and the whole protein landscape is built from the dynamics of successive individual spectra. By applying our approach on bovine serum albumin, we show that single protein subdomains are mostly comprised of three distinct amino acids. Surface amino acids such as lysine are preferentially detected in the open form of the protein. The investigation of the tryptophan Fermi doublet in the single protein regime is highly instructive on the protein conformation. We finally demonstrate that spectral pointillism enables to correlate individual amino acids with structural information.
在本论文中，我们对蛋白质等大分子单分子的表面增强拉曼光谱（SERS）的时间波动提供了新的见解。由于它们只能部分地适配到小的活性体积中，SERS分析被称为光谱点彩法，其中只有蛋白质亚结构域被照亮，而整个蛋白质的全貌是由连续的单个光谱的动态变化构建而成的。通过将我们的方法应用于牛血清白蛋白，我们表明单个蛋白质亚结构域主要由三种不同的氨基酸组成。诸如赖氨酸等表面氨基酸在蛋白质的开放形式中更容易被检测到。对单蛋白质体系中色氨酸费米双峰的研究对于蛋白质构象具有很高的指导意义。我们最终证明光谱点彩法能够将单个氨基酸与结构信息关联起来。
