Thiol-containing biomolecule

Thiol-containing biomolecules are organic molecules that contain at least one sulfhydryl (–SH) group, which imparts chemical reactivity enabling participation in redox reactions, protein folding (disulfide bonding), cellular metabolism, and protection against oxidative stress. Members of this highly heterogeneous class range from small molecules (such as cysteine, glutathione, homocysteine) to cofactors (coenzyme A, lipoic acid), to peptides unique to specific taxa (e.g., trypanothione, mycothiol). Cysteine thiol groups are critical for protein structure and enzyme catalysis; glutathione functions as a central antioxidant in virtually all aerobic life forms. Thiol modifications (oxidation, S-glutathionylation, S-nitrosylation) are key regulators of cell signaling, stress responses, and disease pathology. Many pathogens utilize distinctive thiol chemistry, making their thiol-containing enzymes potential drug targets. Because this term covers a functional group—not a single molecular entity—it is not suitable as a specific drug target, but information on redox-active thiols is essential in biochemistry, medicine, and pharmacology for understanding oxidative stress, cellular defense mechanisms, and redox-targeted therapeutics.

Other names

Mercaptan-containing biomoleculeSulfhydryl-containing compoundSH-bearing molecule

Redox cycling and detoxification; Disulfide bond exchange or reduction; Scavenging reactive oxygen species and electrophiles; Chelation of heavy metals