Glutathione (GSH)

Glutathione (GSH) is a low molecular weight thiol-containing tripeptide composed of L-glutamate, L-cysteine, and glycine. This molecule is endogenously synthesized in mammalian cells and is notable for the unique gamma-glutamyl bond between the carboxyl group of the glutamate side chain and the amine group of cysteine. The presence of a free thiol group on the cysteine residue enables its function as a potent reducing agent. Historically, the discovery and characterization of glutathione date back to the early 20th century, with its structure being fully elucidated in 1930. Subsequent research has extensively explored its multifaceted roles in cellular biochemistry. Its reduced form (GSH) can be oxidized to glutathione disulfide (GSSG) through the action of glutathione peroxidase, a reaction central to its antioxidant capacity. In research contexts, GSH is investigated for its involvement in cellular defense against oxidative stress, regulation of protein function through S-glutathionylation, and participation in xenobiotic metabolism. Its biochemical properties make it a key subject in studies exploring cellular signaling, enzyme activity, and the mechanisms of various biological processes.