Technologies for the identification and validation of protein-protein interactions

Proteins are large molecules that play essential roles in all living organisms. In most molecular processes in each cell, proteins usually do not function alone but through physiological interactions with various ligands. The most common interacting molecules for proteins are other proteins, and they act together by protein-protein interactions (PPIs) to create larger protein complexes. The impairment of physiological PPIs or establishing PPIs with pathological proteins often leads to the development of diseases. To bring insights on the knowledge about the physiological functions of proteins in biological processes, and to understand the development and pathogenesis of diseases, numerous qualitative and quantitative methods have been developed. In this review, we summarize the most commonly used methods for studying PPIs, and discuss their advantages and drawbacks.