Cellular thiol groups (-SH)

Cellular thiol groups are functional moieties characterized by a sulfur atom bonded to a hydrogen atom (-SH), playing a central role in biochemistry and pharmacology (Pompella et al., 2003). They are found in low-molecular-weight molecules like glutathione and within the cysteine residues of proteins, where they facilitate redox signaling, enzymatic catalysis, and the formation of stabilizing disulfide bonds (Circu & Aw, 2010). These groups serve as the primary defense against oxidative stress by scavenging reactive oxygen and nitrogen species, thereby maintaining the cellular reductive environment. In clinical contexts, cellular thiols are significant targets; for instance, elevated glutathione levels in tumor cells are associated with resistance to alkylating agents and platinum-based chemotherapy (Rushworth & Megson, 2014). Conversely, drugs like N-acetylcysteine are used to replenish thiol pools during acetaminophen overdose or to break disulfide bonds in mucus (StatPearls, 2023). Additionally, the high affinity of thiols for heavy metals makes them the primary target for chelating agents used in treating lead or mercury toxicity (NIH/PubChem).

Other names

Sulfhydryl groupsMercapto groupsProtein thiolsNon-protein thiolsCellular sulfhydryls

Nucleophilic conjugation, redox scavenging, metal chelation, and disulfide bond modulation