Advances in Native Chemical Ligation-Desulfurization: A Powerful Strategy for Peptide and Protein Synthesis.

Cysteine-based native chemical ligation (NCL) has been a very powerful approach for convergent synthesis of peptides and proteins. However, owing to the low abundance of cysteine (Cys) in proteins, applications of NCL in protein chemical synthesis are limited. To expand the peptide ligation toolbox, NCL followed by desulfurization has been developed to enable peptide ligation at Xaa-Ala conjunctions, that is, formal "alanine ligation". In this regard, effective peptide desulfurization methods are critical. This Concept article summarizes the development of different desulfurization strategies for peptide and protein chemical synthesis.