Molecular recognition and screening using a 15N group selective STD NMR method
Molecular recognition and screening using a 15N group selective STD NMR method
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DOI：
10.1021/ja073291l
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发表时间：
2007-09-19
影响因子：
15
通讯作者：
Batta, Gyula
中科院分区：
文献类型：
--
作者：
Kover, Katalin E.;Groves, Patrick;Batta, Gyula
我们提出了一种新的饱和转移差（STD）实验，其中实现了N-15标记宿主中酰胺质子的基团选择性（GS）饱和。它表明，一个列车的BIRDd脉冲，反转仅连接到N-15的质子确实导致饱和的酰胺质子，而背景质子磁化的影响要小得多。未标记质子的部分饱和的不期望的效果可以通过在共振频率和非共振频率之间切换N-15载流子而在差谱中完全抵消。因此，获得干净且无伪影的STD光谱，而不需要耗时的实验参数优化和在不存在宿主的情况下获取对照光谱。使用N-15-GS STD实验的情况下，证明了糖肽抗生素（二聚伊瑞霉素）-细胞壁类似物肽（N-Ac-D-Ala）模型系统的主机和客人H-1信号重叠。该应用程序似乎是可行的配体筛选蛋白质没有一个干净的共振频率或定义的配体库的先决条件。新的实验可以作为研究分子间相互作用的基础，其中标准STD实验难以优化。
We present a novel saturation transfer difference (STD) experiment where group selective (GS) saturation of amide protons in N-15 labeled hosts is achieved. It is demonstrated that a train of BIRDd pulses that inverts only protons attached to N-15 indeed results in saturation of the amide protons, while the background proton magnetization is much less affected. The undesired effect of partial saturation of the unlabeled protons can be completely cancelled out in difference spectra by switching the N-15 carrier between the on- and the off-resonance frequencies. As a result, clean and artifact-free STD spectra are obtained without the need of time-consuming optimization of experimental parameters and acquiring control spectra in the absence of the host. The use of the N-15-GS STD experiment is demonstrated for the case of a glycopeptide antibiotic (dimeric eremomycin)-cell-wall analogue peptide (N-Ac-D-Ala) model system where the host and guest H-1 signals overlap. The application seems feasible for ligand screening against proteins without the prerequisite of a clean on-resonance frequency or defined ligand library. The new experiment can be used as the basis for studying intermolecular interactions where the standard STD experiment is difficult to optimize.