Determination of Homo- and Heteronuclear Coupling Constants in Uniformly13C,15N-Labeled DNA Oligonucleotides

A set of experiments to determine homo- and heteronuclear vicinal coupling constants in uniformly C-13-labeled DNA oligonucleotides is presented, 2D and 3D HCCH-E.COSY experiments were used to measure 3J(HH) coupling constants in the deoxyribose ring, a refocused HMBC experiment was used to measure (3)J(CH) coupling constants about the glycosidic torsion angle chi and a P-FIDS-CT-HSQC experiment was used to determine 2J(CP) and 3J(HP) coupling constants about the backbone torsion angle epsilon. The experiments were demonstrated on a uniformly C-13,N-15-labeled 10 base pair (bp) DNA duplex which contains a dA . dT tract 4 bp in length. With these experiments it was possible to extract a number of the coupling constants from duplex DNA.