On protein to protein interactions in the human body

Amazing stuff! Apparently we are still in the very early stages of better understanding PPIs! "But out of this complexity comes opportunity. "

"... Proteins rarely work alone. From tightly bound complexes to passing transitory contacts, interactions between proteins play a central role in the function of the cell. By one estimate, there are over 650,000 protein–protein interactions in the human body. This overwhelming array of interactions represents an almost untapped resource of targets for new therapeutic drugs. ...
High-resolution structures of protein–protein interactions (PPIs) in the 1980s and 90s showed that the interfaces were large, flat featureless surfaces. This was entirely different from the deep pockets found in typical drug targets, such as enzymes and receptors, where small molecules can easily bind. ...
By mutating thousands of individual amino acids at protein–protein interfaces, biochemists found that only a small subset of residues was mostly responsible for binding. These ‘hot spots’ were much more relevant to the strength of the interaction than the size of the interaction surface. ..."

Engineering a handshake for proteins | Feature | Chemistry World Once considered undruggable, chemists are beginning to grasp protein–protein interactions