Low-power high-resolution solid-state NMR of peptides and proteins

We demonstrate that two-dimensional solid-state NMR chemical-shift correlation spectra can be recorded under low-power conditions. Except for the cross-polarization period, no rf-field amplitudes above 40 kHz are used. Such experiments require the use of fast (>50 kHz) magic-angle spinning (MAS). A comparison with the high-power version of the experiment shows no general line broadening but some changes in the polarization-transfer dynamics.