Measurement of 15N relaxation in deuterated amide groups in proteins using direct nitrogen detection.
Measurement of 15N relaxation in deuterated amide groups in proteins using direct nitrogen detection.
复制标题
使用直接氮检测测量蛋白质中氘代酰胺基团的 15N 弛豫。
DOI：
10.1007/s10858-006-9063-4
复制
发表时间：
2006
影响因子：
2.7
通讯作者：
Fushman,David
中科院分区：
文献类型：
--
作者：
Vasos,PaulR;Hall,JenniferB;Kümmerle,Rainer;Fushman,David
15N chemical shielding tensors contain useful structural information, and their knowledge is essential for accurate analysis of protein backbone dynamics. The anisotropic component (CSA) of15N chemical shielding can be obtained from15N relaxation measurements in solution. However, the predominant contribution to nitrogen relaxation from15N–1H dipolar coupling in amide groups limits the sensitivity of these measurements to the actual CSA values. Here we present nitrogen-detected NMR experiments for measuring15N relaxation in deuterated amide groups in proteins, where the dipolar contribution to15N relaxation is significantly reduced by the deuteration. Under these conditions nitrogen spin relaxation becomes a sensitive probe for variations in15N chemical shielding tensors. Using the nitrogen direct-detection experiments we measured the rates of longitudinal and transverse15N relaxation for backbone amides in protein G in D2O at 11.7 T. The measured relaxation rates are validated by comparing the overall rotational diffusion tensor obtained from these data with that from the conventional15N relaxation measurements in H2O. This analysis revealed a 17–24° angle between the NH-bond and the unique axis of the15N chemical shielding tensor.
