Studying the structure and dynamics of biomolecules by using soluble paramagnetic probes

Abstract

Characterisation of the structure and dynamics of large biomolecules and biomolecular complexes by NMR spectroscopy is hampered by increasing overlap and severe broadening of NMR signals. As a consequence, the number of available NMR spectroscopy data is often sparse and new approaches to provide complementary NMR spectroscopy data are needed. Paramagnetic relaxation enhancements (PREs) obtained from inert and soluble paramagnetic probes (solvent PREs) provide detailed quantitative information about the solvent accessibility of NMR-active nuclei. Solvent PREs can be easily measured without modification of the biomolecule; are sensitive to molecular structure and dynamics; and are therefore becoming increasingly powerful for the study of biomolecules, such as proteins, nucleic acids, ligands and their complexes in solution. In this Minireview, we give an overview of the available solvent PRE probes and discuss their applications for structural and dynamic characterisation of biomolecules and biomolecular complexes. Snapshot of the future: The measurement of solvent paramagnetic relaxation enhancements (sPRE) is a powerful and versatile method in the biomolecular NMR spectroscopy toolkit (see picture). sPRE can complement sparse data obtained from other NMR spectroscopy methods with minimal extra experimental setup costs. An overview of the theory and applications of sPRE in structural biology is presented. © 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.