Direct Observation of Hydrogen Bonds in Nucleic Acid Base Pairs by Internucleotide 2JNN Couplings

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• 作者：Andrew J. Dingley and Stephan Grzesiek
• 刊名：Journal of the American Chemical Society
• 出版年：1998
• 出版时间：August 26, 1998
• 年：1998
• 卷：120
• 期：33
• 页码：8293 - 8297
• 全文大小：109K
• 年卷期：v.120,no.33(August 26, 1998)
• ISSN：1520-5126

文摘

Hydrogen bonds play a key role in the stabilization of protein and nucleic acid secondary structure.Currently, most of the experimental evidence for the interaction of hydrogen bond donor and acceptor atomsis indirect. Here we show that scalar couplings across the hydrogen bond are observable for Watson-Crickbase pairs in ¹⁵N-labeled RNA. These scalar couplings correlate the imino donor ¹⁵N nucleus and thecorresponding acceptor ¹⁵N nucleus on the complementary base. The two-bond J_NN couplings between theN3 of uridine and the N1 of adenosine, and between the N1 of guanosine and the N3 of cytidine, have valuesof approximately 7 Hz as determined by a novel quantitative J-correlation experiment for the 69-nucleotideT1 domain of the potato spindle tuber viroid. In contrast, for non-Watson-Crick base pairs the hydrogenbond acceptor is usually not a nitrogen, but an oxygen atom, and thus, the two-bond J_NN couplings are notobserved.