Sulfhydryl and Disulfide Groups of Proteins

(Written for the original Russian edition) Out of all the functional groups of protein molecules that be­ long to the side chains of amino acid residues, the sulfhydryl or thiol (SH) groups of cysteine residues and the disulfide (S-S) groups of cystine have for long attracted particular attention from chemists and biochemists. This is due, on the one hand, to the high chemical reactivity of these ...