Cellular protein thiols and glutathione (GSH) (GSH)

Cellular protein thiols and glutathione (GSH) constitute the fundamental antioxidant defense system and redox buffer within eukaryotic cells. Glutathione, a tripeptide composed of gamma-glutamate, cysteine, and glycine, serves as a major non-protein thiol that neutralizes reactive oxygen species and detoxifies xenobiotics through conjugation reactions [Source: PubChem, CID 124886]. Protein thiols, specifically the sulfhydryl groups of cysteine residues, are vital for maintaining protein structure and function, and they act as molecular switches in redox signaling pathways [Source: PubMed, PMID 30114474]. Dysregulation of the thiol-disulfide balance is a hallmark of various pathologies, including neurodegenerative disorders like Parkinson's disease and chronic inflammatory conditions [Source: NIH, PMC4684116]. Therapeutic strategies targeting this system include the administration of GSH precursors like N-acetylcysteine to restore antioxidant capacity or the use of electrophilic agents like dimethyl fumarate that modulate the Nrf2 pathway via thiol modification [Source: StatPearls, NBK537183]. Conversely, certain chemotherapeutics and toxins interact with these thiols to induce oxidative stress or form DNA-damaging intermediates [Source: PubMed, PMID 22503688]. Monitoring the ratio of reduced to oxidized glutathione is a common method for assessing cellular oxidative stress and the efficacy of thiol-modulating therapies [Source: PubMed, PMID 25470011]. Overall, this target system is central to both cytoprotective and cytotoxic pharmacological approaches across multiple therapeutic areas.

Other names

Sulfhydryl groupsIntracellular thiol poolRedox bufferGlutathione systemP-SH

Drugs targeting this system act by replenishing the glutathione pool to enhance antioxidant capacity, depleting glutathione to sensitize cells to oxidative stress, or covalently modifying protein thiols to alter signaling pathways and enzymatic activities.