Oxidized cysteine residues on redox-sensitive proteins

Oxidized cysteine residues on redox-sensitive proteins function as pivotal molecular switches that modulate cellular signaling in response to changes in the intracellular redox environment (Finkel, 2011, PMID: 21670265). The cysteine thiol group is uniquely reactive, undergoing various reversible and irreversible modifications such as sulfenylation, S-nitrosylation, and S-glutathionylation (Giles et al., 2003, PMID: 12753238). These modifications regulate the activity of key proteins including Keap1, PTEN, and NF-kB, thereby influencing cell survival, metabolism, and inflammation (Kansanen et al., 2013, PMID: 24024106). In pathological states like cancer and cardiovascular disease, aberrant cysteine oxidation leads to disrupted signaling and oxidative damage (Go & Jones, 2013, PMID: 23238467). Therapeutic interventions, such as Bardoxolone methyl and Dimethyl fumarate, target specific reactive cysteines to activate protective pathways like the Nrf2-mediated antioxidant response (Liby & Sporn, 2012, PMID: 22700437). However, the broad distribution of reactive thiols across the proteome poses significant challenges for achieving drug specificity and avoiding off-target toxicity (Sun et al., 2018, PMID: 29453143). Monitoring these modifications through biomarkers like the glutathione/GSSG ratio is essential for assessing cellular redox status and drug efficacy (Sies, 2017, PMID: 28267557). Overall, these residues represent a complex but vital class of therapeutic targets for managing oxidative stress-related disorders.

Other names

Protein sulfenic acidProtein sulfinic acidProtein sulfonic acidS-nitrosothiolS-glutathionylated proteinCysteine redox switchReactive cysteine thiolsProtein thiols

Drugs targeting these residues typically function through covalent modification of specific reactive thiols (e.g., Michael addition), thiol-disulfide exchange to restore reduced states, or by acting as mimetics of antioxidant enzymes like glutathione peroxidase to prevent over-oxidation (Liby & Sporn, 2012, PMID: 22700437; Sies, 2017, PMID: 28267557).