A low-E magic angle spinning probe for biological solid state NMR at 750 MHz
A low-E magic angle spinning probe for biological solid state NMR at 750 MHz
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DOI：
10.1016/j.jmr.2008.12.008
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发表时间：
2009-04-01
影响因子：
2.2
通讯作者：
Long, Joanna R.
中科院分区：
文献类型：
--
作者：
McNeill, Seth A.;Gor'kov, Peter L.;Long, Joanna R.
交叉线圈核磁共振探头是减少生物固体核磁共振样品加热的有效工具。在交叉线圈探头中，高频H-1场是传统探头中样品加热的主要来源，由一个单独的低电感谐振器产生。由于需要较小的驱动电压，因此降低了样品上的电场和由此产生的加热。在这项工作中，我们描述了一种利用双谐振腔的魔角旋转(MAS)固态核磁共振探头的研制。这种被称为“Low-E”的双谐振器方法最初是为了减少机械对准薄膜样品的加热而开发的。通过MAS技术研究固有稀薄体系，如脂质双层中的蛋白质，需要高场下的大样本体积才能在生理相关条件下获得具有足够信噪比的光谱。使用Low-E方法，我们能够在H-1频率为750 MHz的4 mm探头中获得均匀且足够强的H-1和C-13频率的射频场。使用无窗偶极重耦合序列的探针的性能在模型化合物和膜包埋肽上得到了演示。(C)2008 Elsevier Inc.保留所有权利。
Crossed-coil NMR probes are a useful tool for reducing sample heating for biological solid state NMR. In a crossed-coil probe, the higher frequency H-1 field, which is the primary Source of sample heating in conventional probes, is produced by a separate low-inductance resonator. Because a smaller driving voltage is required, the electric field across the sample and the resultant heating is reduced. In this work we describe the development of a magic angle spinning (MAS) solid state NMR probe utilizing a dual resonator. This dual resonator approach, referred to as "low-E," was originally developed to reduce heating in samples of mechanically aligned membranes. The study of inherently dilute systems, such as proteins in lipid bilayers, via MAS techniques requires large sample Volumes at high field to obtain spectra with adequate signal-to-noise ratio under physiologically relevant conditions. With the low-E approach, we are able to obtain homogeneous and Sufficiently strong radiofrequency fields for both H-1 and C-13 frequencies in a 4 mm probe with a H-1 frequency of 750 MHz. The performance of the probe using windowless dipolar recoupling sequences is demonstrated on model compounds as well as membrane-embedded peptides. (C) 2008 Elsevier Inc. All rights reserved.