Selective Modification of Tryptophan Residues in Peptides and Proteins Using a Biomimetic Electron Transfer Process.

ABSTRACT: We report here a photochemical process for the selective modification of tryptophan (Trp) residues in peptides and small proteins using electron-responsive N-carbamoylpyridinium salts and UV-B light. Preliminary mechanistic experiments suggest that the photoconjugation process proceeds through photoinduced electron transfer (PET) between Trp and the pyridinium salt, followed by fragmentation of the pyridinium N-N bond and concomitant transfer of this group to Trp. The reaction displays excellent site selectivity for Trp and is tolerant to other, redox-active amino-acid residues. Moreover, the reaction proceeds in pure aqueous conditions without the requirement of organic cosolvents or photocatalysts, is enhanced by glutathione, and operates efficiently over a wide range of peptide c

SUBMITTER: Tower SJ 

PROVIDER: S-EPMC7292481 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature