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Updated: Jun 14, 2025

Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry
Published on: July 20, 2016
Mild Lewis-Acid-Promoted Cysteine-Tryptophan Conjugation Involving a Radical Process
Qingqing Lu1, Hongyan Wen1, Qinshuo Zhang1
1Key Laboratory of Molecular Synthesis and Function Discovery, College of Chemistry, Fuzhou University, Fuzhou 350108, China.
Abstract:
Numerous methods have been developed for peptide synthesis due to their great potential in drug discovery. However, the technique for tryptophan-cysteine conjugation is still underexplored. Herein, we present a TMSBr-promoted ligation of tryptophan and cysteine under mild conditions by using a sulfonate-modified cysteine substrate. This protocol features a broad scope and high site selectivity and is applicable for synthesis of cyclic peptide. Preliminary mechanistic studies reveal that the reaction proceeds via a radical process.
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