Intramolecular 1H–13C distance measurement in uniformly 13C, 15N labeled peptides by solid-state NMR

Abstract

A 1H–13C frequency-selective REDOR (FS-REDOR) experiment is developed for measuring intramolecular 1H–13C distances in uniformly 13C, 15N-labeled molecules. Theory and simulations show that the experiment removes the interfering homonuclear 1H–1H, 13C–13C and heteronuclear 1H–15N, 13C–15N dipolar interactions while retaining the desired heteronuclear 1H–13C dipolar interaction. Our results indicate that this technique, combined with the numerical fitting, can be used to measure a 1H–13C distance up to 5Å. We also demonstrate that the measured intramolecular 1H–13C distances are useful to determine dihedral angles in proteins.