see Protein NMR Spectroscopy – Principles and Practice by J. Cavanagh, W. Fairbrother, A.G. Palmer III and N.J. Skleton (Academic Press). (Link to Publisher)
Minimum labelling: none
Magnetisation is exchanged between all hydrogens using the NOE.
This spectrum can be used both to help assignment (especially of aromatic residues) and to get structural restraints. It can get very crowded for large proteins, but can nonetheless provide some useful constraints for methyl and aromatic hydrogens. The quality can be improved by using D2O as the solvent, though this means that the exchangable NH protons will not be visible.