Oxidative Modification of Tryptophan-Containing Peptides
journal contributionposted on 2018-05-02, 00:00 authored by Jonas Petersen, Katrine E. Christensen, Mathias T. Nielsen, Kim T. Mortensen, Vitaly V. Komnatnyy, Thomas E. Nielsen, Katrine Qvortrup
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.