Comparison of 1H-13C correlation spectra obtained from deuterated, specifically Phe-labelled TET2 at 55 kHz MAS and of protonated, 13C,15N-labelled TET2 at 103 kHz MAS frequency. The simplification of the spectra of the specifically labelled samples are due to narrower line widths, resulting from the removal of 13C-13C scalar couplings and the better suppression of dipolar line broadening due to surrounding proton spins, and the absence of correlations other than those of ortho-CH or para-CH sites. Note that the spectrum at 103 kHz MAS was at an effective sample temperature of ca. 35°C, i.e., ca. 7°C higher than the ones collected at 55 kHz, which likely explains differences in peak positions.