Efficient acquisition of high-resolution 4-D diagonal-suppressed methyl-methyl NOESY for large proteins.
Efficient acquisition of high-resolution 4-D diagonal-suppressed methyl-methyl NOESY for large proteins.
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DOI：
10.1016/j.jmr.2012.02.021
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发表时间：
2012-05
期刊：
影响因子：
--
通讯作者：
Wu J
中科院分区：
文献类型：
--
作者：
Wen J;Zhou P;Wu J
甲基-甲基NOESY实验在确定大蛋白质的全局折叠中起着重要作用。尽管该实验的高灵敏度，但甲基-甲基NOE的分析经常受到甲基基团，特别是甲基质子的有限化学位移分散的阻碍。这使得使用3D光谱法明确分配所有甲基-甲基NOE交叉变得困难。近年来，稀疏采样方法的发展使得高分辨率四维光谱的高效获取成为可能，这为解决甲基信号的简并性提供了一个很好的解决方案。然而，用于处理稀疏采样的NMR数据的许多重建算法在存在强NOE对角信号的情况下不提供对混叠伪影的充分抑制。为了克服这一局限性，我们提出了一个4-D对角抑制甲基NOESY实验，专门优化超解析采样和评估它使用氘代，ILV甲基质子化的样品的42 kDa的大肠杆菌麦芽糖结合蛋白（MBP）。对角信号的抑制消除了甲基-甲基NOESY实验的动态范围障碍，使得可以进一步减少CLEAN重建的高分辨率4-D光谱中的残余混叠伪影。在小于1%的超解析采样率下，我们能够识别并明确分配绝大多数预期的NOE交叉，甲基之间的间隔小于5 μ m，并检测到非常弱的NOE交叉，甲基间隔超过7 μ m。
The methyl–methyl NOESY experiment plays an important role in determining the global folds of large proteins. Despite the high sensitivity of this experiment, the analysis of methyl–methyl NOEs is frequently hindered by the limited chemical shift dispersion of methyl groups, particularly methyl protons. This makes it difficult to unambiguously assign all of the methyl–methyl NOE crosspeaks using 3-D spectroscopy. The recent development of sparse sampling methods enables highly efficient acquisition of high-resolution 4-D spectra, which provides an excellent solution to resolving the degeneracy of methyl signals. However, many reconstruction algorithms for processing sparsely-sampled NMR data do not provide adequate suppression of aliasing artifacts in the presence of strong NOE diagonal signals. In order to overcome this limitation, we present a 4-D diagonal-suppressed methyl–methyl NOESY experiment specifically optimized for ultrasparse sampling and evaluate it using a deuterated, ILV methyl-protonated sample of the 42 kDa Escherichia coli maltose binding protein (MBP). Suppression of diagonal signals removes the dynamic range barrier of the methyl–methyl NOESY experiment such that residual aliasing artifacts in the CLEAN-reconstructed high-resolution 4-D spectrum can be further reduced. At an ultrasparse sampling rate of less than 1%, we were able to identify and unambiguously assign the vast majority of expected NOE crosspeaks between methyl groups separated by less than 5 Å and to detect very weak NOE crosspeaks from methyl groups that are over 7 Å apart.
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影响因子：
2.7
作者：
Hyberts SG;Frueh DP;Arthanari H;Wagner G
通讯作者：
Wagner G
影响因子：
2.2
作者：
Meissner, A;Sorensen, OW
通讯作者：
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DOI：
10.1073/pnas.96.9.4918
发表时间：
1999-04-27
影响因子：
11.1
作者：
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通讯作者：
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影响因子：
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通讯作者：
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影响因子：
2.7
作者：
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通讯作者：
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