Paramagnetic NMR restraints for the characterization of protein structural rearrangements

Mobility is a common feature of biomacromolecules, often fundamental for their function. Thus, in many cases, bio-macromolecules cannot be described by a single conforma-tion, but rather by a conformational ensemble. NMR paramagnetic data demonstrated quite informative to monitor this conformational variability, especially when used in conjunction with data from different sources. Due to their long-range nature, paramagnetic data can, for instance, i) clearly demonstrate the occurrence of conformational rearrange-ments, ii) reveal the presence of minor conformational states, sampled only for a short time, iii) indicate the most represen-tative conformations within the conformational ensemble sampled by the molecule, iv) provide an upper limit to the weight of each conformation.

Automated summary

Mobility is a crucial feature for the function of biomacromolecules, leading to a conformational ensemble rather than a single conformation. NMR paramagnetic data, especially when combined with other data sources, provide valuable information to monitor the conformational variability. By virtue of their long-range nature, paramagnetic data can demonstrate conformational rearrangements, reveal minor conformational states, indicate representative conformations, and provide upper limits for each conformation's weight.