Thiol-dependent enzyme (generic, see below for specific family variants like "Cysteine protease", "Thiolase", etc.) (None universally; varies for specific enzymes (e.g., PDI for protein disulfide isomerase, CP for cysteine proteases))

Thiol-dependent enzymes encompass a diverse set of proteins whose catalytic activity depends on a reactive cysteine thiol, often forming the basis for hydrolysis, oxidation-reduction, or acyl-transfer chemistry. Major classes include cysteine proteases (e.g., papain, cathepsins), thiolases (important in fatty acid metabolism), and oxidoreductases such as protein disulfide isomerase and thioredoxin-dependent enzymes. Their active-site cysteine can reversibly interact with substrates or inhibitors, making them attractive for drug discovery in diseases involving proteolysis, oxidative stress, or abnormal signaling. However, the term "thiol-dependent enzyme" is generic and captures many unrelated families; therapeutic targeting requires further specification of the enzyme and its cellular context.

Other names

Cysteine-dependent enzymeThiol enzymeSH-enzymeCysteine protease (for a major subfamily)Protein disulfide isomeraseThiolase

Irreversible alkylation or oxidation of the catalytic cysteine; Competitive inhibition of substrate binding; Redox modulation (altering enzyme activity via disulfide bond formation or reduction)