Xia Youlin, Yee Adelinda, Arrowsmith Cheryl H, Gao Xiaolian
Department of Chemistry, University of Houston, Houston, TX 77004-5003, U.S.A.
J Biomol NMR. 2003 Nov;27(3):193-203. doi: 10.1023/a:1025407905478.
Simultaneous data acquisition in time-sharing (TS) multi-dimensional NMR experiments has been shown an effective means to reduce experimental time, and thus to accelerate structure determination of proteins. This has been accomplished by spin evolution time-sharing of the X and Y heteronuclei, such as (15)N and (13)C, in one of the time dimensions. In this work, we report a new 3D TS experiment, which allows simultaneous (13)C and (15)N spin labeling coherence in both t(1) and t(2) dimensions to give four NOESY spectra in a single 3D experiment. These spectra represent total NOE correlations between (1)H(N) and (1)H(C) resonances. This strategy of double time-sharing (2TS) results in an overall four-fold reduction in experimental time compared with its conventional counterpart. This 3D 2TS CN-CN-H HSQC-NOESY-HSQC pulse sequence also demonstrates improvements in water suppression, (15)N spectral resolution and sensitivity, which were developed based on 2D TS CN-H HSQC and 3D TS H-CN-H NOESY-HSQC experiments. Combining the 3D TS and the 3D 2TS NOESY experiments, NOE assignment ambiguities and errors are considerably reduced. These results will be useful for rapid protein structure determination to complement the effort of discerning the functions of diverse genomic proteins.
在分时（TS）多维核磁共振实验中同时进行数据采集已被证明是减少实验时间从而加速蛋白质结构测定的有效方法。这是通过在其中一个时间维度上对X和Y异核（如¹⁵N和¹³C）进行自旋演化分时来实现的。在这项工作中，我们报告了一种新的3D TS实验，该实验允许在t₁和t₂维度上同时进行¹³C和¹⁵N自旋标记相干，从而在单个3D实验中获得四个NOESY谱。这些谱代表了¹H(N)和¹H(C)共振之间的总NOE相关性。与传统方法相比，这种双重分时（2TS）策略使实验时间总体减少了四倍。这种3D 2TS CN-CN-H HSQC-NOESY-HSQC脉冲序列还在水抑制、¹⁵N谱分辨率和灵敏度方面有所改进，它是基于2D TS CN-H HSQC和3D TS H-CN-H NOESY-HSQC实验开发的。结合3D TS和3D 2TS NOESY实验，NOE归属的模糊性和误差大大降低。这些结果将有助于快速进行蛋白质结构测定，以补充识别各种基因组蛋白质功能的工作。
