Methanethiosulfonates (MTS) are a group of reagents which allow the site-selective modification of accessible cysteine residues in proteins.1 Synthesis of compounds carrying the MTS moiety has allowed the covalent attachment of structures to protein surfaces which represent functional mimics of post-translational modifications.2
Here we describe the synthesis of ethyl-linked O-glycosyl methanethiosulfates which allow the selective incorporation of fully deprotected carbohydrate structures onto protein scaffolds.3,4
See figure in Figures section.