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Updated: Nov 23, 2025

Chemical Modification of the Tryptophan Residue in a Recombinant Ca2+-ATPase N-domain for Studying Tryptophan-ANS FRET
Published on: October 9, 2021
Photochemical Chemoselective Alkylation of Tryptophan-Containing Peptides
Benjamin Laroche1, Xinjun Tang1, Gaétan Archer1
1ICIQ - Institute of Chemical Research of Catalonia, the Barcelona Institute of Science and Technology, Avinguda Països Catalans 16, 43007 Tarragona, Spain.
Abstract:
We report a photochemical method for the chemoselective radical functionalization of tryptophan (Trp)-containing peptides. The method exploits the photoactivity of an electron donor-acceptor complex generated between the tryptophan unit and pyridinium salts. Irradiation with weak light (390 nm) generates radical intermediates right next to the targeted Trp amino acid, facilitating a proximity-driven radical functionalization. This protocol exhibits high chemoselectivity for Trp residues over other amino acids and tolerates biocompatible conditions.
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