Structure-Free Validation of Residual Dipolar Coupling and Paramagnetic Relaxation Enhancement Measurements of Disordered Proteins.
Structure-Free Validation of Residual Dipolar Coupling and Paramagnetic Relaxation Enhancement Measurements of Disordered Proteins.
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无序蛋白质的残余偶极耦合和顺磁弛豫增强测量的无结构验证。
DOI：
10.1021/acs.biochem.5b00670
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发表时间：
2015
期刊：
影响因子：
2.9
通讯作者：
Vendruscolo M.
中科院分区：
文献类型：
--
作者：
Newby FN;De Simone A;Yagi-Utsumi M;Salvatella X;Dobson CM;Vendruscolo M.
残留偶极耦合（RDC）和顺磁弛豫增强（PREs）已成为有价值的参数，用于定义无序蛋白质的结构和动力学的核磁共振（NMR）光谱。然而，由于记录RDC所需的对齐介质的存在，或测量PRE必须引入的顺磁性基团的存在，测量它们的程序可能会导致构象扰动。我们在这里讨论通过考虑与阿尔茨海默病相关的40-残基β淀粉样肽（Aβ40）异构体的情况来定量这些影响的实验方法。通过在一定浓度范围内对某些配向介质进行RDC测量，我们表明可以表征Aβ40瞬时结合引起的扰动，从而进行适当的校正。此外，通过使用NMR实验敏感的长程相互作用，我们表明，它是可能的，以确定相对非扰动的网站连接氮氧自由基的PRE测量。因此，最大限度地减少由RDC和PRE测量引入的构象扰动，应有助于它们用于无序蛋白质构象性质的严格测定。
Residual dipolar couplings (RDCs) and paramagnetic relaxation enhancements (PREs) have emerged as valuable parameters for defining the structures and dynamics of disordered proteins by nuclear magnetic resonance (NMR) spectroscopy. Procedures for their measurement, however, may lead to conformational perturbations because of the presence of the alignment media necessary for recording RDCs, or of the paramagnetic groups that must be introduced for measuring PREs. We discuss here experimental methods for quantifying these effects by considering the case of the 40-residue isoform of the amyloid β peptide (Aβ40), which is associated with Alzheimer’s disease. By conducting RDC measurements over a range of concentrations of certain alignment media, we show that perturbations arising from transient binding of Aβ40 can be characterized, allowing appropriate corrections to be made. In addition, by using NMR experiments sensitive to long-range interactions, we show that it is possible to identify relatively nonperturbing sites for attaching nitroxide radicals for PRE measurements. Thus, minimizing the conformational perturbations introduced by RDC and PRE measurements should facilitate their use for the rigorous determination of the conformational properties of disordered proteins.