在魔角旋转下通过频率选择性偶极重耦合确定均匀标记分子的三维结构

Three-dimensional structure determination of a uniformly labeled molecule by frequency-selective dipolar recoupling under magic-angle spinning.

作者信息

Nomura K, Takegoshi K, Terao T, Uchida K, Kainosho M

机构信息

Department of Chemistry, Graduate School of Science, Kyoto University, Japan.

出版信息

J Biomol NMR. 2000 Jun;17(2):111-23. doi: 10.1023/a:1008398906753.

DOI:10.1023/a:1008398906753

PMID:10921776

Abstract

The complete three-dimensional (3D) structure of a glycylisoleucine (Gly-Ile) molecule was determined by individually measuring six dihedral angles with a frequency-selective homonuclear dipolar recoupling method, R2TR (rotational resonance in the tilted rotating frame), using a powder sample of diluted uniformly 13C,15N-labeled Gly-Ile. Each dihedral angle was obtained by recoupling a dipolar interaction between three or four bonds distant spins concerned or observing a dipolar correlation 2D powder pattern. The 3D structure of a Gly-Ile molecule was also determined by X-ray crystallography, and a good agreement with the NMR result was obtained. The results demonstrate that the R2TR method in a uniformly labeled powder sample can provide the 3D structure without the need to prepare a lot of selectively labeled samples.

摘要

采用频率选择性同核偶极重耦合方法R2TR（倾斜旋转坐标系中的旋转共振），通过单独测量六个二面角，利用稀释的均匀13C、15N标记甘氨酰异亮氨酸（Gly-Ile）粉末样品，确定了Gly-Ile分子的完整三维（3D）结构。每个二面角通过重新耦合相隔三个或四个键的自旋之间的偶极相互作用或观察偶极相关二维粉末图谱获得。还通过X射线晶体学确定了Gly-Ile分子的3D结构，并且与核磁共振结果取得了良好的一致性。结果表明，在均匀标记的粉末样品中，R2TR方法无需制备大量选择性标记样品即可提供3D结构。