Viennet, T., et al., Selective Protein Hyperpolarization in Cell Lysates Using Targeted Dynamic Nuclear Polarization. Angew Chem Int Ed Engl, 2016. 55(36): p. 10746-50.Viennet, T., et al., Selective Protein Hyperpolarization in Cell Lysates Using Targeted Dynamic Nuclear Polarization. Angew Chem Int Ed Engl, 2016. 55(36): p. 10746-50.
Nuclear magnetic resonance (NMR) spectroscopy has the intrinsic capabilities to investigate proteins in native environments. In general, however, NMR relies on non-natural protein purity and concentration to increase the desired signal over the background. We here report on the efficient and specific hyperpolarization of low amounts of a target protein in a large isotope-labeled background by combining dynamic nuclear polarization (DNP) and the selectivity of protein interactions. Using a biradical-labeled ligand, we were able to direct the hyperpolarization to the protein of interest, maintaining comparable signal enhancement with about 400-fold less radicals than conventionally used. We could selectively filter out our target protein directly from crude cell lysate obtained from only 8 mL of fully isotope-enriched cell culture. Our approach offers effective means to study proteins with atomic resolution in increasingly native concentrations and environments.