High-resolution solid-state NMR studies on uniformly [13C,15N]-labeled ubiquitin

Understanding of the effects of intermolecular interactions, molecular dynamics, and sample preparation on high-resolution magic-angle spinning NMR data is currently limited. Using the example of a uniformly [C-13, N-15]-labeled sample of ubiquitin, we discuss solid-state NMR methods tailored to the construction of 3D molecular structure and study the influence of solid phase protein preparation on solid-state NMR spectra. A comparative analysis of C-13, C-13 alpha, and C-13 beta resonance frequencies suggests that C-13 chemical-shift variations are most likely to occur in protein regions that exhibit an enhanced degree of molecular mobility. Our results can be refined by additional solid-state MR techniques and serve as a reference for ongoing efforts to characterize the structure and dynamics of (membrane) proteins, protein complexes, and other biomolecules by high-resolution solid-state NMR.