Cellular proteins containing reactive thiol groups

Cellular proteins containing reactive thiol groups represent a broad functional class of proteins where the sulfhydryl (-SH) group of cysteine residues is critical for biological activity. These thiols are highly nucleophilic and serve as essential components in redox signaling, antioxidant defense, and enzymatic catalysis (Giles et al., 2003). Many proteins use these reactive groups as 'redox switches,' where oxidation or modification of the thiol alters the protein's conformation and function in response to cellular stress (Circu & Aw, 2010). In pharmacology, these groups are targeted by various electrophilic agents, heavy metals, and certain chemotherapeutics that form covalent bonds with the sulfur atom, thereby inhibiting enzyme activity or disrupting protein-protein interactions (PubChem). For example, arsenic trioxide exerts its therapeutic effects in leukemia by binding to vicinal thiols in specific proteins like PML-RARalpha (NIH). However, the widespread distribution of reactive thiols across the human proteome presents significant challenges for drug design, as non-specific binding can lead to systemic toxicity and off-target effects.

Other names

Protein thiolsSulfhydryl-containing proteinsCysteine thiolsReactive protein sulfhydryls

Covalent modification of cysteine sulfhydryl groups through alkylation, oxidation, or coordination with metal ions.