Glutathione
Glutathione — A tripeptide (Glu-Cys-Gly) and the primary intracellular antioxidant, studied for its role in oxidative stress protection and detoxification.
What Is Glutathione?
Glutathione (GSH) is a tripeptide with the sequence gamma-Glu-Cys-Gly and a molecular weight of 307.32 Da. It is the most abundant intracellular antioxidant in mammalian cells, present at concentrations of 1-10 mM. The gamma-peptide bond between glutamate and cysteine (linking the side-chain carboxyl rather than the alpha-carboxyl) makes glutathione resistant to normal proteolytic cleavage.
Mechanism of Action
Glutathione functions through its free thiol group on the cysteine residue. It directly neutralizes reactive oxygen species (ROS) and serves as a cofactor for glutathione peroxidase and glutathione S-transferase enzymes. The oxidized form (GSSG) is recycled back to GSH by glutathione reductase using NADPH, maintaining the cellular redox balance.
Research Applications
- Oxidative stress: GSH/GSSG ratio is the primary biomarker of cellular redox status
- Detoxification: Phase II conjugation of xenobiotics and drug metabolites via glutathione S-transferase
- Immune function: Lymphocyte proliferation and NK cell activity require adequate GSH levels
- Neuroprotection: GSH depletion is associated with neurodegenerative disease models
Handling
Reduced glutathione (GSH) is highly susceptible to oxidation. Store lyophilized at -20°C under inert gas. Reconstitute immediately before use. Solutions rapidly oxidize to GSSG at neutral pH; acidify to pH 4-5 for short-term storage or add chelators (EDTA) to prevent metal-catalyzed oxidation.
Frequently Asked Questions
What is Glutathione?
A tripeptide (Glu-Cys-Gly) and the primary intracellular antioxidant, studied for its role in oxidative stress protection and detoxification.
Why is Glutathione important in peptide research?
Glutathione is a fundamental concept in compound as it relates to peptide science. It directly influences experimental design, compound characterization, and the reliability of research outcomes across biochemistry and molecular biology disciplines.