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. © 1996 by John Wiley & Sons, Ltd.