Thiol-containing enzyme or protein (no single canonical name; describes a class) (None (multiple abbreviations exist for specific members, e.g., Cys for cysteine; "thiol protease" or "PDI" for protein disulfide isomerase))

Thiol-containing enzymes and proteins are a **diverse group** of biomolecules characterized by the presence of **thiol (—SH) groups**, mainly in the amino acid cysteine[1][2][6]. These thiols are crucial for protein structure via **disulfide bond formation**, **enzymatic catalysis**, **redox regulation**, and cellular signaling. Important subclasses include **cysteine proteases** (which degrade proteins), **redox enzymes** (such as thioredoxin and protein disulfide isomerase, which regulate disulfide bond formation and reduction), and **small molecule thiols** like glutathione (central to antioxidant defense). Thiol groups can be post-translationally modified, affecting their function in signal transduction and stress response. This group is essential across biology and medicine, involved in development, disease, and therapeutic intervention, but "thiol-containing enzymes and proteins" is not a precise molecular target—it requires specification to particular proteins or enzymes for detailed study or drug development[1][3][4][6].

Other names

Thiol enzymeCysteine-containing proteinSulfhydryl enzymeMercaptan proteinRedox-active protein

Competitive inhibition of active site cysteine thiol (for protease inhibitors); Covalent modification of thiol groups (alkylation or oxidation); Redox cycling (reduction or oxidation of thiol groups, modulation of enzyme activity); Chelation and sequestration of heavy metals by thiolate formation