Chemoselective modification of proteins: hitting the target.

The use of synthetic molecules to modulate and track biological events is a central component of chemical biology. As a result, the precise, covalent modification of biomolecules is a key goal for this field. Several strategies have emerged that allow specific tailoring of polypeptides through either endogenous residues or introduced functionality. This tutorial review discusses these recent advances in the context of in vitro and in vivo applications.