NMR Spectroscopy

With its ability to study macromolecules in the aqueous state, NMR is a powerful adjunct to X-ray crystallography and the two techniques are highly complementary. Protein structure determination is routine on proteins less than 40 kDa and, using higher field magnets, doable up to almost 100 kDa. Additionally, the analysis of NMR relaxation rates can be used to quantitatively describe molecular motions in solution, allowing the identification and characterization of minor structural states that make large contributions to function. Lastly, NMR is commonly used to monitor protein conformational changes and ligand-binding reactions.