Experimental methods to study the kinetics of protein–protein interactions

Studying the kinetics of protein–protein interaction is crucial to understand the nature, stability, dynamics, and biological significance of protein complexes. It provides an opportunity to analyze their kinetic behavior and determine their therapeutic potential. Several experimental methods have been developed to study the protein–protein interaction kinetics, allowing flexibility to choose the best suitable method according to the requirements. Each method has its own advantages and limitations. For example, surface plasmon resonance (SPR), bio-layer interferometry (BLI), and quartz crystal microbalance (QCM) require immobilization of one of the binding partners, while others like isothermal titration calorimetry (ITC) and microscale thermophoresis (MST) can assess the interactions in solution. Furthermore, SPR, QCM, and ITC are label-free approaches, while MST requires fluorescence labeling. In this chapter, we summarize these common biophysical techniques to study the kinetics of protein–protein interactions.