Oxidative modification of tryptophan-containing peptides

• Main Authors: Petersen, Jonas, Christensen, Katrine E., Nielsen, Mathias T., Mortensen, Kim T., Komnatnyy, Vitaly V., Nielsen, Thomas Eiland, Qvortrup, Katrine
• Other Authors: Singapore Centre for Environmental Life Sciences and Engineering
• Format: Article
• Language: English
• Published: 2020
• Subjects: Engineering::Environmental engineering; Solid-phase Peptide Synthesis; Fluorescent Labeling
• Online Access: https://hdl.handle.net/10356/140152
• Institution: Nanyang Technological University

We herein present a broadly useful method for the chemoselective modification of a wide range of tryptophan-containing peptides. Exposing a tryptophan-containing peptide to 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) resulted in a selective cyclodehydration between the peptide backbone and the indole side chain of tryptophan to form a fully conjugated indolyl-oxazole moiety. The modified peptides show a characteristic and significant emission maximum at 425 nm, thus making the method a useful strategy for fluorescence labeling.