ABSTRACT
Although glutathione (GSH) is established as the major small thiol compound in most cell types, and although the combination of reduced and oxidized glutathione (GSH + GSSG) is the major thiohdisulfide redox couple of the cell and implicated in many processes (see other contributions to this volume), there are still some surprising gaps in our knowledge of the involvement of these compounds in cellular physiology. Two related areas of ignorance concern the subcellular distribution of GSH and GSSG and the nature of the net oxidant involved in the conversion of cysteine residues in nascent polypeptide chains into disulfide-bonded cystine residues in secretory proteins and in the extracellular domains of cell-surface proteins.
