Improved resolution in 1H-detected 1H-15N correlation experiments.

The determination of protein structure by NMR is restricted at molecular masses above 10 kDa by overlapping resonances. One way of overcoming this problem is to label the protein with 15N. The conventional way to record 15N spectra is to use heteronuclear multiple-quantum coherence. We present here an alternative approach based on 15N single-quantum coherence. This is shown to have substantial advantages over the multiple-quantum method, including better F1 resolution.