A new experiment for the measurement of (n)J(C,P) coupling constants including (3)J(C4(i)('),P-i) and (3)J(C4(i)('),Pi+1) in oligonucleotides

A new experiment for the measurement of (n)J(C,P) coupling constants along the phosphodiester backbone in RNA and DNA based on a quantitative-J HCP experiment is presented. In addition to coupling constants, in which a carbon atom couples to only one phosphorus atom, both the intraresidual (3)J(C4(i)',Pi) and the sequential (3)J(C4(i)',Pi+1) for the C4' resonances that couple to two phosphorus atoms can be obtained. Coupling constants obtained by this new method are compared to values obtained from the P-FIDS experiment. Together with (3)J(H,P) coupling constants measured using the P-FIDS experiment, the backbone angles beta and epsilon can be determined.