Optimizing resolution in multidimensional NMR by three-way decomposition
Optimizing resolution in multidimensional NMR by three-way decomposition
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DOI：
10.1023/a:1024944720653
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发表时间：
2003-10-01
影响因子：
2.7
通讯作者：
Billeter, M
中科院分区：
文献类型：
--
作者：
Orekhov, VY;Ibraghimov, I;Billeter, M
分辨率取决于在FID中采样的点数；在间接检测的维度中，它是总实验时间的重要决定因素。基于核磁共振数据中存在的高冗余度，我们提出了以下用于三维光谱的省时方案。使用了离散T1和T2值的广泛网格，这在保持光谱宽度的同时提高了分辨率。通过避免为选定的T1和T2对记录T3-FID，减少了总的实验时间；通常对于大约75%的(T1，T2)组合省略了记录。这些数据集被称为稀疏，实验后处理最佳地利用光谱冗余来提供丢失的、未记录的数据。我们之前已经证明，MUNIN方法中的三向分解(TWD)为处理密集的核磁共振数据集提供了一种实用的方法。这里，一个新的TWD算法[Ibraghimov，(2002)Numer.线性代数应用。9,551-565]用于通过为实验中省略的所有(T1，T2)组合提供缺失的FID来补充稀疏记录的时域数据集。一个必要条件是，对于每个T1值，至少记录几个FID，并且对于每个T2值都是类似的。该方法是在非均匀采样的N-15-NOESY-HSQC数据集上为14kD的天青蛋白记录的。尽管NOESYs具有大量的信号和高的动态范围，但通过TWD、重建和普通到频域的变换获得的光谱与记录了所有(T1，T2)组合的对应的参考光谱高度相似。
Resolution depends on the number of points sampled in a FID; in indirectly detected dimensions it is an important determinant of the total experiment time. Based on the high redundancy present in NMR data, we propose the following timesaving scheme for three-dimensional spectra. An extensive grid of discrete t1- and t2-values is used, which increases resolution while preserving the spectral width. Total experiment time is reduced by avoiding the recording of t3-FIDs for selected pairs of t1 and t2; typically the recording is omitted for about 75% of the (t1, t2) combinations. These data sets are referred to as sparse, and post-experimental processing making optimal use of spectral redundancy provides the missing, non-recorded data. We have previously shown that three-way decomposition (TWD) within the MUNIN approach provides a practical way to process dense NMR data sets. Here, a novel TWD algorithm [Ibraghimov, (2002) Numer. Linear Algebra Appl. 9, 551-565] is used to complement a sparsely recorded time-domain data set by providing the missing FIDs for all (t1, t2) combinations omitted in the experiment. A necessary condition is that for each t1- value at least a few FIDs are recorded, and similar for each t2-value. The method is demonstrated on non-uniformly sampled N-15-NOESY-HSQC data sets recorded for the 14 kD protein azurin. The spectra obtained by TWD, reconstruction and ordinary transform to frequency-domain are, in spite of the large number of signals and the high dynamic range typical for NOESYs, highly similar to a corresponding reference spectrum, for which all (t1, t2) combinations were recorded.