Determination of Homo‐ and Heteronuclear Coupling Constants in Uniformly 13C,15N‐Labeled DNA Oligonucleotides

A set of experiments to determine homo‐ and heteronuclear vicinal coupling constants in uniformly 13C‐labeled DNA oligonucleotides is presented. 2D and 3D HCCH‐E.COSY experiments were used to measure 3JHH coupling constants in the deoxyribose ring, a refocused HMBC experiment was used to measure 3JCH coupling constants about the glycosidic torsion angle χ and a P‐FIDS‐CT‐HSQC experiment was used to determine 2JCP and 3JHP coupling constants about the backbone torsion angle ε. The experiments were demonstrated on a uniformly 13C,15N‐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.