General cellular sulfhydryl-containing proteins and redox systems (Cellular Thiol/Redox Systems)

General cellular sulfhydryl-containing proteins and redox systems represent a broad collective of molecules, including glutathione (GSH), thioredoxins, and various enzymes with reactive cysteine residues that maintain the intracellular reducing environment. These systems are critical for protecting cells against oxidative damage, regulating protein function through reversible thiol-disulfide exchange, and modulating signal transduction pathways sensitive to redox changes (NIH, 2023). In many diseases, particularly cancer and chronic inflammation, these redox systems are often upregulated to compensate for increased oxidative stress, making them attractive but challenging therapeutic targets (PubMed, PMID: 31504044). Pharmacological intervention often involves electrophilic drugs that covalently bind to these sulfhydryl groups, thereby inhibiting essential enzymes like thioredoxin reductase or depleting the cellular pool of reduced glutathione. While this approach can effectively induce apoptosis in malignant cells, the lack of specificity for a single protein often leads to significant safety concerns and off-target effects (StatPearls, 2023). Consequently, while these systems are recognized as therapeutic targets, they are generally considered a 'class' of targets rather than a single molecular entity.

Other names

Protein sulfhydrylsCellular thiolsThiol-redox systemProtein-bound thiolsRedox-active cysteines

Drugs typically interact with these systems through covalent modification (alkylation or oxidation) of reactive cysteine thiol groups, leading to the inhibition of redox-sensitive enzymes, depletion of antioxidant capacity, or induction of the electrophilic stress response.