Nuclear Magnetic Resonance ( NMR ) Spectroscopy: Structure Determination of Proteins and Nucleic Acids

Abstract

Abstract Nuclear magnetic resonance (NMR) spectroscopy is a powerful biophysical technique that facilitates determination of the three‐dimensional structure and interactions of proteins and nucleic acids in solution. A set of NMR experiments identifies spectral signatures corresponding to specific atoms on individual residues in the molecule and determines their order in the primary sequence. Distance and angular relationships are subsequently measured and utilized to supplement standard force‐fields used in molecular dynamics (MD)‐based protocols to obtain high‐resolution structural models. Structure determination is aided by molecular biology and biochemistry to generate samples optimally labelled with NMR‐active isotopes; by improvement in the design of NMR instrumentation to allow spectral signatures to be recorded with high sensitivity; by development of efficient techniques to manipulate nuclear spins at the quantum level; and by generation of advanced computer algorithms that allow rapid processing, manipulation and storage of large quantities of NMR data. Key Concepts: Solution NMR is an excellent spectroscopic technique for the determination of the three‐dimensional structure of biomolecules at near‐physiological conditions. The abundance of chemical and structural information available from NMR spectra derives from the ability to selectively manipulate specific nuclei by customizable sequences of radio‐frequency pulses in a large static magnetic field. NMR signals report on the variety of chemical environments experienced by nuclei in biomolecules through unique spectral signatures. The repertoire of information‐rich NMR experiments has been expanded by the ability to enrich biomolecules with NMR‐active nuclei taking advantage of advances in molecular biology and biochemistry. Nuclear spins in biomolecules form magnetically coupled networks, with characteristic spectral profiles that can be manipulated to extract angular, orientational and distance information for calculation of three‐dimensional structural models.