High-resolution heteronuclear correlation spectroscopy in solid state NMR of aligned samples.

A new two-dimensional scheme is proposed for accurate measurements of high-resolution chemical shifts and heteronuclear dipolar couplings in NMR of aligned samples. Both the 1H chemical shifts and the 1H–15N dipolar couplings are evolved in the indirect dimension while the 15N chemical shifts are detected. This heteronuclear correlation (HETCOR) spectroscopy yields high-resolution 1H chemical shifts split by the 1H–15N dipolar couplings in the indirect dimension and the 15N chemical shifts in the observed dimension. The advantages of the HETCOR technique are illustrated for a static 15N-acetyl-valine crystal sample and a 15N-labeled helical peptide sample aligned in hydrated lipid bilayers.