Molecular Recognition and Screening Using a 15N Group Selective STD NMR Method

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• 作者：Katalin E. Kö ; vé ; r ; Patrick Groves ; Jesú ; s Jimé ; nez-Barbero ; Gyula Batta
• 刊名：Journal of the American Chemical Society
• 出版年：2007
• 出版时间：September 19, 2007
• 年：2007
• 卷：129
• 期：37
• 页码：11579 - 11582
• 全文大小：97K
• 年卷期：v.129,no.37(September 19, 2007)
• ISSN：1520-5126

文摘

We present a novel saturation transfer difference (STD) experiment where group selective (GS)saturation of amide protons in ¹⁵N labeled hosts is achieved. It is demonstrated that a train of BIRD^d pulsesthat inverts only protons attached to ¹⁵N indeed results in saturation of the amide protons, while thebackground proton magnetization is much less affected. The undesired effect of partial saturation of theunlabeled protons can be completely cancelled out in difference spectra by switching the ¹⁵N carrier betweenthe on- and the off-resonance frequencies. As a result, clean and artifact-free STD spectra are obtainedwithout the need of time-consuming optimization of experimental parameters and acquiring control spectrain the absence of the host. The use of the ¹⁵N-GS STD experiment is demonstrated for the case of aglycopeptide antibiotic (dimeric eremomycin)-cell-wall analogue peptide (N-Ac-D-Ala) model system wherethe host and guest ¹H signals overlap. The application seems feasible for ligand screening against proteinswithout the prerequisite of a clean on-resonance frequency or defined ligand library. The new experimentcan be used as the basis for studying intermolecular interactions where the standard STD experiment isdifficult to optimize.