Preformed Selenoesters Enable Rapid Native Chemical Ligation at Intractable Sites

摘要

The discovery of native chemical ligation (NCL) by Kent and co-workers in 1994 was a critical step, enabling researchers to chemically access medium-sized proteins through total or semi-synthesis. Virtually hundreds of proteins have now been prepared by the NCL method ranging in size from small polypeptides to medium-sized proteins of more than 200 amino acids. The original conceptual framework of NCL is based on the reaction between an unprotected peptide with a C-terminal thioester and another unprotected peptide carrying an N-terminal cysteine (Scheme 1b).