Simplification of DNA proton nuclear magnetic resonance spectra by homonuclear Hartmann-Hahn edited two-dimensional nuclear Overhauser enhancement spectroscopy

Two-dimensional {sup 1}H NMR spectra of DNA fragments in solution supply a wealth of structural information. The first step in establishing the molecular structure using NMR spectroscopy is the assignment of protons to a particular nucleotide residue. Sequential assignment procedures using a combination of NOESY and COSY have been developed which allow straightforward assignment of the base and most of the sugar protons in short DNA oligonucleotides which adopt a right-handed A- or B-DNA type structure. In order to simplify the NOESY spectra of DNA oligonucleotides for assignment purposes, the authors present an experiment that enables one to selectively trace the NOE connectivities of cytidine H6 resonances. This approach substantially simplifies the analysis of a 2D NOE spectrum in the base to sugar proton regions and allows straightforward identification of corresponding resonances.