Cysteine thiol group in protein

Cysteine thiols in proteins refer to the side chain (-SH group) of cysteine residues present throughout the proteome. These thiol groups play critical roles in biological chemistry due to their unique redox reactivity, nucleophilicity, and ability to form disulfide bonds or coordinate metals[3][6]. In proteins, cysteine thiols contribute to enzymatic catalysis (as nucleophilic centers), maintain protein structure via disulfide bridges, serve as redox switches subjected to various oxidative post-translational modifications (such as sulfenylation, S-nitrosylation, and glutathionylation), and regulate signaling pathways critical for cell proliferation, apoptosis, and immunity[4][1][5]. Aberrant modification or oxidation of cysteine thiols is implicated in numerous diseases, including cancer and neurodegeneration[7]. Drugs often target reactive cysteine thiols in enzyme active sites or redox-sensitive proteins by covalent alkylation or by modulating their redox state. “Cysteine thiols in various proteins” is not a single druggable target, but rather a broad chemical moiety present in many distinct proteins, making it a challenging and non-specific therapeutic target[3][6].

Other names

Protein cysteine residuesProtein thiol groupsProtein sulfhydryl groups

Thiol oxidation or reduction; Alkylation of reactive cysteine residues; Disulfide bond modulation; Metal chelation via cysteine-coordination