Noncellular screening for the discovery of protein-protein interaction modulators

Protein-protein interactions (PPIs) constitute many potential therapeutic targets for the discovery of new drugs. Given their specificity, PPIs are more challenging to target than other ligands. Thus, finding the best screening process can be difficult. Moreover, PPIs often have no direct accessible activity readout. Therefore, it can be unclear which test to choose for the screening of small molecules targeting PPIs. Given that noncellular assays are the most suitable both as first screening assays and for high-throughput screening (HTS), here we focus on noncellular screening assays. For each assay, we discuss the principles and advantages/drawbacks and provide a recent example. We also highlight the crucial parameters to take into account to select the most suitable assays to screen PPI modulators.