A novel NMR spectroscopy technique for studying microsecond protein motions using proton off-resonance spin locks has recently been reported in the 'Journal of the American Chemical Society' (JACS). This breakthrough overcomes a major limitation in proton relaxation dispersion measurements, which previously suffered from strong spin diffusion effects that blurred site-specific motional information.
By employing off-resonance spin locks, the researchers effectively reduced proton–proton crosstalk, facilitating qualitative access to microsecond timescale motion exclusively through protons. This innovation eliminates the necessity for heteronuclear isotope labeling and opens up new possibilities for investigating molecular dynamics in both biology and materials The technique, which involves fast magic-angle spinning and proton near-rotary-resonance dispersion (NERRD), provides highly versatile observables absent in solution NMR. It allows for the detection of site-specific microsecond timescale fluctuations of anisotropic interactions, offering unique insights into regional proton dipolar-coupling networks around a given site.
This discovery not only enhances the understanding of molecular dynamics but also paves the way for more advanced and efficient NMR spectroscopy techniques, with potential applications in drug design, materials science, and beyond.