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Updated: Jul 6, 2026

Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins
Published on: October 4, 2017
Facile conversion of cysteine and alkyl cysteines to dehydroalanine on protein surfaces: versatile and switchable
Gonçalo J L Bernardes1, Justin M Chalker, James C Errey
1Chemistry Research Laboratory, Dept. of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK.
Abstract:
An efficient and robust oxidative elimination of cysteine to dehydroalanine has been discovered. The reaction is induced by O-mesitylenesulfonylhydroxylamine (MSH) and is compatible with methionine. The key elimination has been executed on protein surfaces and allows ready access to different post-translationally modified proteins through conjugate addition of sulfur nucleophiles to dehydroalanine. Treatment of the resulting thioether with MSH results in regeneration of dehydroalanine, allowing a "functional switch" by subsequent addition of a different thiol.
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