1H assisted 13C/15N heteronuclear correlation spectroscopy in oriented sample solid-state NMR of single crystal and magnetically aligned samples

(1)H-irradiation under mismatched Hartmann-Hahn conditions provides an alternative mechanism for carrying out (15)N/(13)C transfers in triple-resonance heteronuclear correlation spectroscopy (HETCOR) on stationary samples of single crystals and aligned samples of biopolymers, which improve the efficiency especially when the direct (15)N-(13)C dipolar couplings are small. In many cases, the sensitivity is improved by taking advantage of the (13)C(α) labeled sites in peptides and proteins with (13)C detection. The similarities between experimental and simulated spectra demonstrate the validity of the recoupling mechanism and identify the potential for applying these experiments to virus particles or membrane proteins in phospholipid bilayers; however, further development is needed in order to derive quantitative distance and angular constraints from these measurements.