13C-n.m.r. study of C hordein.

The structure of C hordein was studied by a combination of solution and solid-state 13C-n.m.r. spectroscopy. The repetitive primary structure results in simple solution-state n.m.r. spectra, which allow assignment of the majority of the resonances to five major residues. The major resonances, with the exception of the aromatic signals, are also present in the solid-state spectra. The proline residues are in the trans configuration, consistent with an earlier study suggesting a beta-turn-rich structure.