High-resolution MAS NMR spectroscopy detection of the spin magnetization exchange by cross-relaxation and chemical exchange in intact cell lines and human tissue specimens
High-resolution MAS NMR spectroscopy detection of the spin magnetization exchange by cross-relaxation and chemical exchange in intact cell lines and human tissue specimens
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DOI：
10.1002/mrm.20889
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发表时间：
2006-06-01
影响因子：
3.3
通讯作者：
Singer, Samuel
中科院分区：
文献类型：
--
作者：
Chen, Jin-Hong;Sambol, Elliot B.;Singer, Samuel
高分辨率魔角旋转(HR-MAS)核磁共振光谱检测完整细胞和组织样本中膜磷脂和蛋白质的分辨信号。只要偶极耦合是“非均匀的”，MAS还有一个额外的优势，那就是只要偶极耦合是“非均匀的”，就可以通过相邻自旋的相互“触发”，通过与时间无关的偶极耦合来猝灭自旋扩散。在MAS下，水与膜磷脂中每个质子位置之间以及水与核磁共振可观察到的蛋白质质子信号之间发生了显著的磁化转移。水与膜磷脂之间的MT速率低于水与蛋白质质子信号之间的MT速率。水与其他小分子的相互作用是选择性的，MT从水到肌酸、乳酸、牛磺酸和甘氨酸，而不是甘油三酯、磷胆碱、胆碱或肌醇。HR-MAS核磁共振可以检测水和肌酸的每个质子基团之间的完整MT网络。在骨骼肌中发现了两个肌酸池(一个运动受限，一个运动自由)。
High-resolution magic-angle-spinning (HR-MAS) NMR spectroscopy detects resolved signals from membrane phospholipids and proteins in intact cell and tissue samples. MAS has the additional advantage of quenching spin-diffusion through a mutual "flip-flop" of neighbor spins by time-independent dipolar coupling as long as the dipolar coupling is "inhomogeneous." Under MAS, significant magnetization transfer (MT) was observed between water and each proton site in membrane phospholipid and between water and the NMR-observable protein proton signals. The MT rates between water and membrane phospholipids are lower than those between water and protein proton signals. The interaction of water to other small molecules is selective with the observation of MT from water to creatine, lactate, taurine, and glycine, but not to triglyceride, phosphocholine, choline, or myo-inositol. HR-MAS NMR allows the detection of a complete MT network between water and each proton group of creatine. Two creatine pools (one motion-restricted and one motion-free) were identified in skeletal muscle.