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

Abstract

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