Nuclear magnetic resonance (NMR) spectroscopy provides detailed information regarding structure and dynamics of protein, RNA and DNA. To determine molecular structures, several NMR experiments are performed to obtain structural “constraints” which are used for computer modeling. The structure of a biomolecule is best understood as an ensemble of structures. The term “biomolecular NMR” refers to the use of NMR to study biological compounds in vivo or more typically under conditions which best mimic in vivo conditions. Samples may be examined in solution (“solution state NMR”) or in the solid state (“solid state NMR”).
NMR generally lacks the sensitivity to detect signals from quantities of samples that are generally available, so biomolecules are often enriched in 13C and/or 15N to detect signal in a reasonable amount of time. Deuterium is often incorporated into proteins or complexes greater than ~35 KDa in size to reduce line-broadening effects brought about from 1H-1H dipolar relaxation. Over the years, advances in isotope-labeling strategies, have expanded the size of macromolecules and the types of detailed information available for study.