Selective correlation of amide groups to glycine alpha protons and of arginine guanidine groups to delta protons in proteins by multiple quantum spectroscopy

A new 3D guise sequence correlates backbone amide proton and nitrogen with alpha proton resonances selectively for glycine residues in a fully doubly labeled (N-15, C-13) protein. The excitation of multiple quantum coherences provides optimized resolution and sensitivity. Degenerate alpha proton gro ups can be promptly recognized. Correlation of guanidine NH groups to delta protons of arginine side chains is also obtained. (C) 1999 Academic Press.