Fig. 5.

2D ¹³C–¹³C correlation spectra of U-¹³C,¹⁵N-LC8 protein acquired at the magnetic field of 20.0 T and MAS frequency of 40 kHz with a fpRFDR_xy16, b CORD_xy4, and c CORD–RFDR. The CORD–RFDR experiment reveals numerous new cross peaks throughout the entire the chemical shift range as compared to fpRFDR_xy16 and CORD_xy4. The Cα region of the CORD–RFDR spectrum shows numerous inter-residue correlations and the aromatic region displays multiple intra-residue side-chain correlations not present in either the CORD or fpRFDR spectra. Assignments of new cross peaks in the various regions of CORD–RFDR spectrum are shown in the magnified views of: d aliphatic region, e aliphatic–aromatic region, f carbonyl region, and g aromatic–carbonyl region. Most of the carbons for which new cross peaks were observed are separated by 3–5 Å (medium-range distance). Several correlations corresponding to long-range distances have been detected as well. Table 2 summarizes the new correlations detected in the CORD–RFDR spectrum