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.