Protein-protein interactions (PPI) play crucial roles in the regulation of cell metabolism. Recent technological advances, based both on in silico predictions or on in vivo testing, enable the isolation and development of small PPI mediators. The latter may comprise small peptides, antibodies, engineered proteins, both synthetically designed or coming from natural organisms and engineered to reach orthogonality. PPI mediators can be then exploited in drug discovery as therapeutics, or to engineer synthetic biological circuits based solely on PPIs (protein circuits).

This Methods Collection aim to collect technical reports and methodologies by which researchers can screen, isolate and/or build natural/synthetic PPI mediators, and other technologies by which these novel PPI can be characterized on high-throughput screenings. Methods which have already an application for the engineered PPI, like synthetic cell-cell adhesion and/or protein targeting (e.g. PROTACs) are of particular interest.