L-Glutathione oxidized

Glutathione can occur in reduced (GSH), oxidized (GSSG), or in mixed disulfide forms and is ubiquitous in multiple biological systems serving as the major thiol-disulfide redox buffer of the cell. Glutathione, Oxidized (GSSG) is the oxidized version of the naturally occurring and very important antioxidant glutathione (GSH). In vivo GSSG is reduced back to GSH via the NADPH-dependent enzyme glutathione reductase. The ratio of GSH to GSSG is often used to gauge the level of oxidative stress in cells, with higher concentrations of GSSG implying more oxidative stress, therefore beeing an important bioindicator of cellular health. GSSG functions as a hydrogen acceptor in the enzymatic determination of NADP+ and NADPH and can be a proximal donor in S-glutathionylation post translational modifications. GSSG, along with glutathione and S-nitrosoglutathione (GSNO), have been found to bind to the glutamate recognition site of the NMDA and AMPA receptors (via their γ-glutamyl moieties), and may be endogenous neuromodulators. GSSG can be used as substrate for enzymatically assaying glutathione reductase.