Protein and cofactor sulfhydryl groups (SH groups) (SH groups)

Protein and cofactor sulfhydryl groups, also known as thiols (-SH), are highly reactive chemical moieties found on the amino acid cysteine and in essential cofactors like glutathione, coenzyme A, and lipoic acid (Source: PubChem). These groups play a fundamental role in biological systems by participating in redox signaling, maintaining protein structure through disulfide bond formation, and serving as catalytic centers in various enzymes (Source: NCBI, "The role of thiols in antioxidant systems"). In pharmacology and toxicology, these groups are significant because they are the primary targets for heavy metal ions, such as mercury, lead, and arsenic, which bind to them with high affinity and disrupt cellular function (Source: StatPearls, "Heavy Metal Toxicity"). Therapeutic interventions often involve the use of chelating agents like dimercaprol, which provide exogenous sulfhydryl groups to sequester toxic metals (Source: FDA Label, Dimercaprol). Additionally, certain drugs like ethacrynic acid or alkylating agents can covalently modify these groups, leading to both therapeutic effects and potential off-target toxicity (Source: DrugBank). Because these groups are ubiquitous across thousands of different proteins, they are generally considered a broad chemical target rather than a specific therapeutic receptor.

Other names

Thiol groupsSulfhydryl groupsMercapto groupsProtein thiolsCysteine sulfhydryl groups

Covalent modification (alkylation/arylation), oxidation to disulfides, or coordination/complexation with metal ions.