Visualizing transient dark states by NMR spectroscopy.
Visualizing transient dark states by NMR spectroscopy.
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DOI：
10.1017/s0033583514000122
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发表时间：
2015-03
影响因子：
6.1
通讯作者：
Clore GM
中科院分区：
文献类型：
--
作者：
Anthis NJ;Clore GM
无数的生物过程通过状态进行，这些状态不符合常规原子分辨率结构生物学方法的特征。这些“暗”态的不可见性可能源于它们的瞬态性质、低平衡粒子数、大分子量和/或异质性。虽然它们是不可见的，但这些暗态是一系列过程的基础，充当蛋白质之间的相遇复合物以及蛋白质折叠和聚集的中间体。新的方法使这些状态可以通过核磁共振（NMR）光谱进行高分辨率分析，只要暗态与NMR可见物质处于动态平衡。这些方法-顺磁NMR，弛豫色散，饱和转移，寿命线加宽和氢交换-允许在一定时间尺度范围内与可见物质交换的其他不可见状态的探索，每种方法都利用暗态的一些独特性质来放大其对特定NMR观察结果的影响。在这篇综述中，我们介绍了这些方法，并探讨了两个具体的技术-顺磁弛豫增强和暗态交换饱和转移-更详细。
Myriad biological processes proceed through states that defy characterization by conventional atomic-resolution structural biological methods. The invisibility of these ‘dark’ states can arise from their transient nature, low equilibrium population, large molecular weight, and/or heterogeneity. Although they are invisible, these dark states underlie a range of processes, acting as encounter complexes between proteins and as intermediates in protein folding and aggregation. New methods have made these states accessible to high-resolution analysis by nuclear magnetic resonance (NMR) spectroscopy, as long as the dark state is in dynamic equilibrium with an NMR-visible species. These methods – paramagnetic NMR, relaxation dispersion, saturation transfer, lifetime line broadening, and hydrogen exchange – allow the exploration of otherwise invisible states in exchange with a visible species over a range of timescales, each taking advantage of some unique property of the dark state to amplify its effect on a particular NMR observable. In this review, we introduce these methods and explore two specific techniques – paramagnetic relaxation enhancement and dark state exchange saturation transfer – in greater detail.