J-modulated 1D directed COSY for precise measurement of proton-proton residual dipolar coupling constants of oligosaccharides

2002 ◽  
Vol 40 (11) ◽  
pp. 729-732 ◽  
Author(s):  
Tran N. Pham ◽  
Tibor Liptaj ◽  
Paul N. Barlow ◽  
Dušan Uhrín
Keyword(s):  
Precise Measurement ◽  
Dipolar Coupling ◽  
Residual Dipolar Coupling ◽  
Coupling Constants ◽  
Proton Proton

The Structure of The Dimethylthallium Ion Oriented in a Lyotropic Nematic Phase

1975 ◽  
Vol 53 (2) ◽  
pp. 161-166 ◽  
Author(s):  
Yunko Lee ◽  
Leonard W. Reeves
Keyword(s):  
Nematic Phase ◽  
Electrostatic Interactions ◽  
Dipolar Coupling ◽  
Coupling Constants ◽  
Scalar Coupling ◽  
Complex Ions ◽  
Proton Proton ◽  
Ionic Detergent ◽  
Degree Of Orientation ◽  
Nematic Phases

The proton magnetic resonance spectra of dimethylthallium ion has been studied in both anionic and cationic detergent nematic phases. The spectra were analyzed to derive the values of inter- and intramethyl proton–proton dipolar coupling and the intermethyl scalar coupling constants. The degree of orientation of the dimethylthallium cation is much higher in the anionic nematic phase than in the cationic phase. It is proposed that electrostatic interactions play a significant role in the orientation of complex ions in ionic detergent nematic phases.

scholarly journals 2-amino-1,3-benzothiazole-6-carboxamide Preferentially Binds the Tandem Mismatch Motif r(UY:GA)

2020 ◽  
Author(s):  
Andrew T. Chang ◽  
Lu Chen ◽  
Luo Song ◽  
Shuxing Zhang ◽  
Edward P. Nikonowicz
Keyword(s):  
Small Molecules ◽  
Dipolar Coupling ◽  
Residual Dipolar Coupling ◽  
Three Dimensional ◽  
Coupling Constants ◽  
Dimensional Structure ◽  
Flanking Sequence ◽  
Base Pairs ◽  
Virtual Screen ◽  
Rna Hairpin

AbstractRNA helices are often punctuated with non-Watson-Crick features that can be the target of chemical compounds, but progress towards identifying small molecules specific for non-canonical elements has been slow. We have used a tandem UU:GA mismatch motif (5’-UG-3’:5’-AU-3’) embedded within the helix of an RNA hairpin as a model to identify compounds that bind the motif specifically. The three-dimensional structure of the RNA hairpin and its interaction with a small molecule compound identified through a virtual screen are presented. The G-A of the mismatch forms a sheared pair upon which the U-U base pair stacks. The hydrogen bond configuration of the U-U pair involves the O2 of the U adjacent to the G and the O4 of the U adjacent to the A. The G-A and U-U pairs are flanked by A-U and G-C base pairs, respectively, and the mismatch exhibits greater stability than when the motif is within the context of other flanking base pairs or when the 5’-3’ orientation of the G-A and U-U is swapped. Residual dipolar coupling constants were used to generate an ensemble of structures against which a virtual screen of 64,480 small molecules was performed to identify candidate compounds that the motif specifically binds. The tandem mismatch was found to be specific for one compound, 2-amino-1,3-benzothiazole-6-carboxamide, which binds with moderate affinity but extends the motif to include the flanking A-U and G-C base pairs. The finding that affinity for the UU:GA mismatch is flanking sequence dependent emphasizes the importance of motif context and potentially increases the number of small non-canonical features within RNA that can be specifically targeted by small molecules.

scholarly journals Precise Measurement of Long-Range Heteronuclear Coupling Constants by a Novel Broadband Proton-Proton-Decoupled CPMG-HSQMBC Method

2015 ◽  
Vol 21 (8) ◽  
pp. 3472-3479 ◽  
Author(s):  
István Timári ◽  
Tünde Z. Illyés ◽  
Ralph W. Adams ◽  
Mathias Nilsson ◽  
László Szilágyi ◽  
...  
Keyword(s):  
Long Range ◽  
Precise Measurement ◽  
Coupling Constants ◽  
Proton Proton ◽  
Heteronuclear Coupling
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