Chapter 1. Theory and Applications of NMR Spectroscopy in Biomolecular Structures and Dynamics of Proteins

Structural biology has come a long way since the first inception of multidimensional NMR. The dipole–dipole interaction between two spatially closed spins provides a powerful tool to probe macromolecules’ three-dimensional (3D) structure, such as proteins. However, the main challenge for macromolecules is to assign the NMR chemical shifts of all signals of the investigated protein. This chapter presents different 3D triple-resonance NMR experiments dedicated to assignments of NMR signals of protein backbone structure. In addition, the through-space correlation experiments, namely NOESY, ROESY, and HOESY, are presented with detailed information about the advantages and limitations of each. The main strength of NMR lies in obtaining molecular structures under natural conditions and detailed information on the molecular dynamics at different timescales. The detailed characterization of sub-nanosecond segmental motions in proteins was characterized long before the advent of the first solution structure by NMR. Herein, the basic concept behind structure determination and elucidating protein dynamics on different timescales is presented. This chapter also highlights the NMR methodologies regarding characterizing sparsely populated protein conformations and transient states, vital for macromolecular functions.