A Cysteine Selenosulfide Redox Switch for Protein Chemical Synthesis

We describe a cyclic selenosulfide derivative of cysteine called SetCys that enables to perform protein chemical synthesis under redox-control.
Native chemical ligation or SEA-mediated ligation with SetCys peptide segments proceeds in a traceless manner and involves the cleavage of a carbon-nitrogen bond in situ.
The manuscript describes detailed mechanistic investigations of SetCys redox-switch and its application to the production of biologically active cyclic protein mimics of hepatocyte growth factor, the high-affinity ligand of MET tyrosine kinase receptor.