General thiol-disulfide exchange substrates

General thiol-disulfide exchange substrates encompass a diverse group of molecules, including small-molecule thiols like glutathione and various proteins, that undergo reversible redox reactions involving the formation and cleavage of disulfide bonds (Gilbert, 1990, Adv. Enzymol. Relat. Areas Mol. Biol.). This chemical process is a cornerstone of cellular redox homeostasis and is critical for the proper folding of secretory proteins within the endoplasmic reticulum (Bulaj, 2005, Biotechnol. Adv.). Thiol-disulfide exchange also serves as a regulatory mechanism for protein function, where the oxidation state of specific cysteine residues acts as a molecular switch to control activity (Hogg, 2003, Trends Biochem. Sci.). While these substrates themselves are not typically considered discrete therapeutic targets, the enzymes that facilitate these exchanges—such as protein disulfide isomerases (PDI) and thioredoxins—are major focal points for drug development in cancer and neurodegeneration (Hogg, 2003, Trends Biochem. Sci.). Pharmacological intervention usually involves small molecules that mimic or compete with these substrates to alter the cellular oxidative environment or inhibit specific protein-folding pathways. Consequently, the term refers more to a biochemical pathway or class of reactants rather than a single druggable receptor or enzyme.

Other names

Thiol-disulfide exchangeDisulfide exchange substratesProtein thiolsProtein disulfidesRedox-active cysteines

Modulation of cellular redox state through the reversible reduction or formation of disulfide bonds via nucleophilic attack by thiolate anions.