DARR - Solid-state Correlation NMR Spectroscopy for Large Molecules -

Structural analysis of large molecules such as proteins using NMR is getting popular in the field of solid-state NMR. DARR (Dipolar Assisted Rotational Resonance) is one of techniques for analyzing large molecules in solids. The method can yield ¹³C-¹³C correlations for ¹³C-labeled samples, leading to intermolecular and intramolecular structures.

Figure shows DARR spectra of ¹³C-labeled bacteriochlorophyll c (BChl c). Different rates of labelling distinguish intermolecular and intramolecular correlations, while variation of mixing times gives information on ¹³C-¹³C distances.

Sample:
100% labelled BChl c (left)
50% labelled BChl c (right)
Spectrometer: JNM-ECA600
Probe:  4mm CPMAS
Mixing time:  200 ms

Reference

Isotopic Replacement of Pigments and a Lipid in Chlorosomes from Chlorobium limicola: Characterization of the Resultant Chlorosomes
Y. Kakitani, K. Harada, T. Mizoguchi, and Y. Koyama, Biochemistry 46, 6513-6524 (2007)

Sample courtesy of