[2] Deuteration in protein proton magnetic resonance

This chapter discusses the deuteration in protein proton magnetic resonance. There are three general patterns of deuterium labeling that in practice serve rather different functions: selective protonation in a deutero background, selective deuteration in a protio background, and random fractional deuteration, in which all carbon-bound hydrogen positions have been uniformly enriched to an intermediate level with deuterium. The chemical means of producing deuterated amino acids can be separated into the generally more facile exchange procedures, which start with the natural abundance amino acid sample, and de novo chemical synthesis. In addition, for amino acids possessing methylene positions, deuteration procedures can be separated according to whether the labeling is stereospecific. A large number of deuteration patterns are accessible for all of the standard amino acids. When combined with the metabolic genetics and protein expression systems as available for E. coli, a truly extraordinary range of deuteration experiments is practical and can allow for detailed nuclear magnetic resonance (NMR) studies that are not feasible using natural abundance samples.