Facile conversion of cysteine and alkyl cysteines to dehydroalanine on protein surfaces: versatile and switchable access to functionalized proteins.
Bernardes GJL., Chalker JM., Errey JC., Davis BG.
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.