Shining a Light on Peptide and Protein Synthesis: Light-Emitting-Diode-Driven Desulfurization of Cysteine to Alanine with Rose Bengal

Studies presenting visible-light-induced desulfurization of peptides containing a cysteine residue have been carried out. This transformation driven by light-emitting-diode-type light proceeds with high efficiency in an aqueous solution at room temperature and involves the use of a catalytic amount of photosensitizer, Rose Bengal. The procedure has been tested on model synthetic peptides, lysozyme C and α-crystallin, and successfully applied to a one-pot native chemical ligation (NCL)-desulfurization protocol.