GENERATION OF IMPOSSIBLE CROSS-PEAKS BETWEEN BULK WATER AND BIOMOLECULES IN SOLUTION NMR
GENERATION OF IMPOSSIBLE CROSS-PEAKS BETWEEN BULK WATER AND BIOMOLECULES IN SOLUTION NMR
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DOI：
10.1126/science.8266096
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发表时间：
1993-12-24
期刊：
影响因子：
56.9
通讯作者：
FARMER, BT
中科院分区：
文献类型：
--
作者：
WARREN, WS;RICHTER, W;FARMER, BT
在适度浓度（20 mM）下，散装水和糖蛋白片段之间的分子间多量子相干性已经在实验中产生并检测到，尽管这种相干性在核磁共振的正常理论框架中是不可想象的。密度矩阵处理解释了这些结果，包括自旋之间的长程偶极相互作用，并通过丢弃高温近似。这些结果意味着，峰强度（关键的结构测定）可以在许多梯度实验中扭曲，并显示魔角梯度提供了实质性的改善与降低梯度强度。他们还提出了在磁共振成像中增强对比度的方法。
Intermolecular multiple-quantum coherences between bulk water and a glycoprotein fragment at modest concentration (20 mM) have been experimentally produced and detected, although such coherences are inconceivable in the normal theoretical framework of nuclear magnetic resonance. A density matrix treatment explains these results by including the long-range dipolar interaction between spins and by discarding the high-temperature approximation. These results imply that peak intensities (critical for structural determinations) can be distorted in many gradient experiments, and show that magic-angle gradients provide substantial improvements with reduced gradient strengths. They also suggest methods for contrast enhancement in magnetic resonance imaging.