Measurement of 1H3'-31P dipolar couplings in a DNA oligonucleotide by constant-time NOESY difference spectroscopy.
The ratios of cross peak intensities in a selective constant-time NOESY experiment, recorded with and without 31P decoupling, yield values for the sum of the H3'-P scalar and dipolar couplings. The selective refocusing of H3' resonances in this experiment results in excellent resolution and sensitivity, even in the liquid crystalline phase where the 1H spectrum is broadened by unresolved homonuclear dipolar couplings. The vicinal H3'-P scalar and dipolar couplings in the DNA oligomer d(CGCGAATTCGCG)2 were measured in both isotropic solution, and in a liquid crystalline phase. Isotropic values are in good agreement with values reported previously. Dipolar couplings are in excellent agreement with the NMR structure for this dodecamer, and to a somewhat lesser extent with the X-ray structures.
Wu
Z
Z
Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Tjandra
N
N
Bax
A
A
D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry*; D017931:DNA Primers / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D010759:Phosphorus Isotopes; D014316:Tritium / Q000737:chemistry
D017931:DNA Primers; D010759:Phosphorus Isotopes; D014316:Tritium; D004247:DNA