Genetically encoded selective cross-linkers and emerging applications.

There has been a large amount of interest in the development of genetically encoded cross-linkers that target functional groups naturally present in cells. Recently, a new class of unnatural amino acids that specifically react with target residues were developed and genetically incorporated. The selective reaction shows higher cross-linking efficiency, lower background and predictable cross-linking sites. It has been applied to enhance protein/peptide stability, pinpoint protein-protein interactions, stabilize protein complexes, engineer covalent protein inhibitors, identify phosphatases in living cells, etc. These new covalent linkages provide excellent new tools for protein engineering and biological studies. Their applications in biotherapy will provide considerable opportunities for innovating and improving biomolecular medicines.