Coupling amplification in 2D MAS NMR and its application to torsion angle determination in peptides
Coupling amplification in 2D MAS NMR and its application to torsion angle determination in peptides
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DOI：
10.1006/jmre.1997.1242
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发表时间：
1997-11-01
影响因子：
2.2
通讯作者：
Schmidt-Rohr, K
中科院分区：
文献类型：
--
作者：
Hong, M;Gross, JD;Schmidt-Rohr, K
本文介绍了一种放大魔角旋转实验中C-13-H-1和N-15-H-1偶极相互作用的表观强度的技术。通过在二维偶极化学位移实验的演化周期中插入转子同步的180 °脉冲，异极偶极耦合相对于旋转速度增加了一倍或四倍，偶极边带数目的增加对于保留间接检测的偶极维度中的结构信息同时在相对高的纺丝速度下分辨各向同性化学位移维度中的不等价位点是期望的，将该偶联扩增方法并入通过C-alpha-H-alpha和N-H-N键的相对取向确定肽扭转角phi的实验中。实验和理论都表明，N-H-N耦合的选择性加倍显著提高了测量的角分辨率。(C)北京：科学出版社.
A technique for amplifying the apparent magnitudes of C-13-H-1 and N-15-H-1 dipolar interactions in magic-angle spinning experiments is described, By inserting rotor-synchronized 180 degrees pulses in the evolution period of a 2D dipolar-chemical shift experiment, heteronuclear dipolar couplings are doubled or quadrupled relative to the spinning speed, The increased number of dipolar sidebands is desirable for retaining structural information in the indirectly detected dipolar dimension while resolving inequivalent sites in the isotropic chemical shift dimension at relatively high spinning speeds, This coupling amplification method is incorporated into an experiment that determines the peptide torsion angle phi through the relative orientation of the C-alpha-H-alpha and N-H-N bonds. It is shown both experimentally and theoretically that the angular resolution of the measurement is enhanced significantly by the selective doubling of the N-H-N coupling. (C) 1997 Academic Press.