The sequence of amino acid residues around the oxidation-reduction active disulfide in yeast glutathione reductase.

A 14-residue peptide containing the oxidation-reduction active cystine residue from yeast glutathione reductase has been isolated from proteolytic digests of the enzyme in which the free sulfhydryl groups had been reacted with N-ethylmaleimide. The sequence of this disulfide-containing peptide was found to be:(see article). The sequence was highly homologous with the active cystine regions in Escherichia coli and pig heart lipoamide dehydrogenase. The sequences of three of the postulated four thiol-containing regions of the enzyme are also presented, as well as evidence supporting the view that the enzyme is composed of two identical subunits.