Cellular proteins containing sulfhydryl groups

Cellular proteins containing sulfhydryl groups represent a broad and non-specific class of molecules characterized by the presence of thiol (-SH) functional groups, primarily found on cysteine residues. These groups are critical for the biological function of a vast array of enzymes and structural proteins, where they participate in catalytic mechanisms, form stabilizing disulfide bridges, and coordinate essential metal ions [1][3]. In pharmacology and toxicology, these proteins are notable as the primary targets for heavy metals such as mercury, lead, and arsenic, which bind with high affinity to sulfhydryl groups, thereby disrupting cellular metabolism and inducing toxicity [2][4]. While certain historical drugs, such as mercurial diuretics, utilized this reactivity to exert their effects, modern drug discovery typically views this category as too broad for targeted therapy due to the high risk of off-target effects. Instead, therapeutic intervention often involves the use of chelating agents like dimercaprol or succimer, which provide exogenous sulfhydryl groups to compete for metal binding and protect endogenous cellular proteins from damage [3][5]. Sources: [1] StatPearls. "Biochemistry, Thiol Groups." NCBI. [2] PubChem. "Mercury (Compound Summary)." National Library of Medicine. [3] StatPearls. "Heavy Metal Toxicity." NCBI. [4] NIH. "Arsenic Toxicity." Agency for Toxic Substances and Disease Registry. [5] LiverTox. "Dimercaprol." National Institute of Diabetes and Digestive and Kidney Diseases.

Other names

Thiol-containing proteinsSulfhydryl-bearing proteinsCysteine-rich proteinsProtein thiols

Drugs or toxins interact with these proteins via covalent modification or coordination of the sulfhydryl (-SH) group on cysteine residues, which can lead to the inhibition of enzymatic activity, alteration of protein conformation, or sequestration of the protein's functional site [1][2].