Comparative studies on the reactions of cysteine, methionine, histidine, and lysine derivatives with allyl bromide, 1-bromo-2-butyne, and 2-bromoacetophenone have been carried out in connection with an evaluation of the potential of reagents incorporating ethylenic and acetylenic functions for protein modification.
Thiol-sulfoxonium ylide photo-click chemistry: an ultrafast and highly cysteine-specific method for protein functionalization and proteome profiling.