Dynamic nuclear polarization (DNP) transfers electron spin-polarization to nuclear spins in close proximity, increasing sensitivity by two-to-three orders of magnitude. This enables nuclear magnetic resonance (NMR) experiments on samples with low concentrations of analyte. The requirement of using cryogenic temperatures in DNP-enhanced solid-state NMR (ssNMR) experiments may impair the resolution and hence limit its broad application to biological systems. In this work, we introduce a "High-Temperature DNP" approach, which aims at increasing spectral resolution by performing experiments at temperatures of around 180 K instead of ~100 K. By utilizing the extraordinary enhancements obtained on deuterated proteins, still sufficiently large DNP enhancements of 11-18 are obtained for proton and carbon, respectively. We recorded high sensitivity 2D ~(13)C- ~(13)C spectra in ~9 min with higher resolution than at 100 K, which has similar resolution to the one obtained at room temperature for some favorable residues.
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