ABSTRACT
The modification of methionine (2-amino-4-thiomethylbutanoic acid) in a protein is generally accomplished with considerable difficulty. This is possibly a reflection of the fact that, as a relatively hydrophobic residue, methionine is frequently buried in a protein. It is somewhat more challenging to obtain the specific modification of methionine under mild physiological conditions, but advances in the past decade have greatly improved potential in this area. It is possible to obtain highly selective oxidation with some reagents in certain proteins, and the results have been useful. Because the dissociation of a proton from sulfur is unnecessary to generate the nucleophile, relatively specific derivatization by alkylating agents can be accomplished at low pH.
