Novel 1H- 31P heteronuclear coherence transfer spectroscopy based on spin locking MLEV-17 and its application to signal assignment for a short DNA fragment

Abstract

We have applied the MLEV-17 proton spin locking pulse to 1H- 31P 2D heteronuclear correlation spectroscopy. Using this technique, long-range correlations between a proton and phosphorus that is up to 5 bonds distant are observed. Thus, the 3′-, 4′- and 5′-proton resonances can be traced ‘sequentially’ along the chain on the 2D NMR chart. Application of this technique to the complete assignment of the sugar proton and phosphorus resonances for d(ApGpA) is reported. This technique can also be used for convenient assignment of the phosphorus resonances of oligonucleotides as correlations between the 1′-proton and its 3′-side phosphorus are observed.