NMR studies of weak protein-protein interactions

A study was conducted to demonstrate how nuclear magnetic resonance (NMR) was used to investigate weak heterotypic protein-protein interactions in which complexes were formed between different proteins rather the homotypic interactions which led to the multimerization of a particular protein. The study described methods for preparing weak protein complexes for NMR studies, and included the different types of isotope labeling required for the investigations along with as the practicalities of making protein-protein complexes that were functionally relevant. Different techniques were also used in the 'titration' mode in investigations of weak interactions where the NMR characteristics were observed as a function of increasing concentrations of a partner protein rather than as a single equilibrium mix with only one protein: protein concentration ratio.