Cunha Ana V, Salamatova Evgeniia, Bloem Elin, Roeters Steven J, Woutersen Sander, Pshenichnikov Maxim S, Jansen Thomas L C
Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.
Van 't Hoff Institute for Molecular Sciences, University of Amsterdam , Science Park 904, 1098XH Amsterdam, The Netherlands.
J Phys Chem Lett. 2017 Jun 1;8(11):2438-2444. doi: 10.1021/acs.jpclett.7b00731. Epub 2017 May 19.
Intrinsically disordered proteins play an important role in biology, and unraveling their labile structure presents a vital challenge. However, the dynamical structure of such proteins thwarts their study by standard techniques such as X-ray diffraction and NMR spectroscopy. Here, we use a neat liquid composed of N-methylacetamide molecules as a model system to elucidate dynamical and structural properties similar to those one can expect to see in intrinsically disordered proteins. To examine the structural dynamics in the neat liquid, we combine molecular dynamics, response-function-based spectral simulations, and two-dimensional polarization-resolved infrared spectroscopy in the amide I (CO stretch) region. The two-dimensional spectra reveal a delicate interplay between hydrogen bonding and intermolecular vibrational coupling effects, observed through a fast anisotropy decay. The present study constitutes a general platform for understanding the structure and dynamics of highly disordered proteins.
内在无序蛋白质在生物学中发挥着重要作用，解析其不稳定结构是一项重大挑战。然而，此类蛋白质的动态结构阻碍了通过诸如X射线衍射和核磁共振光谱等标准技术对其进行研究。在此，我们使用由N-甲基乙酰胺分子组成的纯液体作为模型系统，以阐明与内在无序蛋白质中预期可见的动态和结构特性相似的特性。为了研究纯液体中的结构动力学，我们在酰胺I（CO伸缩）区域结合了分子动力学、基于响应函数的光谱模拟以及二维偏振分辨红外光谱。二维光谱揭示了氢键和分子间振动耦合效应之间的微妙相互作用，这通过快速各向异性衰减得以观察到。本研究构成了一个理解高度无序蛋白质的结构和动力学的通用平台。
