The Use of NMR in the Studies of Highly Flexible States of Proteins: Relation to Protein Function and Stability

The power of NMR as a method for characterizing the solution state of proteins stems from the highly specific way that NMR reports on protein structure and dynamics. This is due to the fact that NMR parameters, such as chemical shifts, relaxation rates and exchange-rate parameters report specifically about the local environment around the investigated nuclei. This obviously requires that the relevant NMR resonances have been assigned to the individual nuclei of the protein structures, which with present day techniques for isotope labeling and multidimensional NMR methods is possible for proteins with molecular weights higher than 30 kDa. After the resonances have been assigned, the overall three-dimensional structure of a protein can be determined from distance and angular constraints derived from additional spectral information.