DETERMINATION OF A COMPLETE SET OF COUPLING-CONSTANTS IN C-13-LABELED OLIGONUCLEOTIDES

Three experiments are introduced to determine a complete set of coupling constants in RNA oligomers. In the HCCH-E.COSY experiment, the vicinal proton-proton coupling constants can be measured with high accuracy. In the P-FIDS-CT-HSQC experiment, vicinal proton-phosphorus and carbon-phosphorus couplings are measured that depend on the phosphodiester backbone torsion angles beta and epsilon. In the refocussed HMBC experiment, vicinal carbon-proton couplings are measured that depend on the glycosidic torsion angle chi.