Takahashi, H., S. Hediger, and G. De Paepe, Matrix-free dynamic nuclear polarization enables solid-state NMR (13)C-(13)C correlation spectroscopy of proteins at natural isotopic abundance. Chem Commun (Camb), 2013. 49(82): p. 9479-81.
We introduce a general approach for dynamic nuclear polarization (DNP) enhanced solid-state NMR that overcomes the current problems in DNP experiments caused by the use of frozen solutions. Notably, we report for the first time a 2D (13)C-(13)C correlation spectrum of a protein without the use of isotopic labeling.