A practical reference on glutathione: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-07-24. Anything still debated is marked as such rather than presented as settled.
Glutathione synthesis proceeds in two ATP-dependent steps catalyzed by glutamate-cysteine ligase and glutathione synthetase. The first step joins glutamate and cysteine to form gamma-glutamylcysteine and is generally rate-limiting. The second step adds glycine to complete the tripeptide. Cysteine availability, feedback inhibition by glutathione, and oxidative conditions influence flux through this pathway. The pathway is conserved across many organisms, and degradation by gamma-glutamyl transpeptidase and related peptidases recycles amino acids for new synthesis.
Within cells, glutathione serves as a cofactor for glutathione peroxidases and glutathione S-transferases. These enzymes reduce hydrogen peroxide and organic peroxides or conjugate electrophilic compounds to the thiol group. The resulting conjugates can be exported and processed through mercapturic acid pathways. Glutathione also contributes to protein thiol homeostasis and to recycling of other antioxidants such as ascorbate. Its precise roles vary by tissue, and many regulatory effects observed in laboratory systems remain difficult to quantify in whole organisms.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. It occurs in nearly all living cells, with highest concentrations in liver, kidney, and red blood cells, and exists in reduced (GSH) and oxidized disulfide (GSSG) forms. The cysteine thiol group enables reversible oxidation and reduction reactions. This property makes glutathione a central participant in cellular redox balance. The balance between these forms is often used as an indicator of oxidative stress.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. The peptide bond between glutamate and cysteine uses the gamma-carboxyl group of glutamate rather than the alpha-carboxyl group. This unusual linkage protects the molecule from many common peptidases. The cysteine side chain carries a thiol group that can undergo reversible oxidation. Because of this thiol, glutathione participates in redox reactions and helps maintain the reducing environment inside most cells in living systems.
In cells, glutathione exists mainly in a reduced form called GSH. When two GSH molecules react, they form oxidized glutathione, or GSSG, which contains a disulfide bond. The ratio of GSH to GSSG is often used as an indicator of oxidative stress. Enzymes such as glutathione peroxidase and glutathione reductase help cycle the molecule between these two states. This cycling supports antioxidant defense, detoxification of reactive molecules, and regulation of certain signaling pathways.
| Property | Value | Notes |
|---|---|---|
| Common name | Glutathione | Reduced form is abbreviated GSH |
| Chemical class | Tripeptide | Composed of glutamate, cysteine, and glycine |
| Molar mass | 307.32 g/mol | For reduced glutathione |
| CAS Registry Number | 70-18-8 | For reduced L-glutathione |
| Appearance | White crystalline powder | Typical solid reference material |
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. Its cysteine residue carries a thiol group, which allows the molecule to participate in reduction and oxidation reactions. The compound exists in most living cells, where the reduced form, often abbreviated GSH, is usually more abundant than the oxidized disulfide form, GSSG. Intracellular concentrations are commonly in the millimolar range, while extracellular concentrations are much lower. This uneven distribution supports its role as a major cellular redox buffer.
Cells synthesize glutathione through two ATP-dependent enzymatic steps. The first step combines glutamate and cysteine to form gamma-glutamylcysteine, catalyzed by glutamate-cysteine ligase. The second step adds glycine, producing the complete tripeptide, catalyzed by glutathione synthetase. Glutathione itself can inhibit the first enzyme, providing negative feedback when levels are high. Because cysteine is often limiting, its availability influences how quickly the pathway proceeds. These reactions occur in the cytosol, and the resulting glutathione can be distributed to other compartments.
Glutathione functions in redox balance, detoxification, and sulfur amino acid storage. It participates in reactions that help maintain ascorbate and protein thiol status. The molecule serves as a cofactor for several enzymes, including glutathione peroxidases and glutathione S-transferases. These enzymes reduce peroxides and conjugate electrophiles, respectively. Glutathione also contributes to the metabolism of xenobiotics and to the transport of cysteine between tissues. How interorgan transport and tissue-specific regulation shape whole-body pools remains an active area of study.
Synthesis occurs in two ATP-dependent steps: glutamate-cysteine ligase joins glutamate and cysteine to form gamma-glutamylcysteine, and glutathione synthetase adds glycine to complete the tripeptide. The pathway is feedback-inhibited by GSH and limited by cysteine availability, so cysteine supply often constrains production. Once formed, GSH participates in redox buffering, xenobiotic conjugation, and protein glutathionylation. Glutathione peroxidase uses GSH to reduce hydrogen peroxide and lipid peroxides, yielding GSSG, while glutathione reductase regenerates GSH using NADPH. Glutathione S-transferases conjugate electrophiles to GSH, supporting detoxification and excretion.
Because GSH is central to redox balance, its status is studied in aging, liver disease, neurodegenerative conditions, and metabolic disorders. Observational studies often report lower GSH or higher GSSG in affected tissues, but such associations do not establish that raising glutathione changes disease outcomes. Oral glutathione is digested into amino acids, and whether intact absorption occurs remains debated; precursors such as N-acetylcysteine and cysteine donors are also investigated. Regulatory agencies generally treat glutathione as a dietary supplement, not an approved drug, and clinical claims require evidence from controlled trials.
Glutathione supports detoxification by conjugating reactive electrophiles through glutathione S-transferases. The resulting conjugates are processed and exported, often after further metabolism. It also stores cysteine, transports amino acids across membranes through the gamma-glutamyl cycle, and assists in the maturation of iron-sulfur clusters and some prostaglandins. In plants, animals, and many microbes, the molecule appears in similar roles, but concentrations vary enormously between tissues. Liver, kidney, and red blood cells tend to contain high amounts, while blood plasma contains much less.
Glutathione is a small tripeptide built from glutamate, cysteine, and glycine. The peptide bond between glutamate and cysteine uses the gamma-carboxyl group, a linkage that resists ordinary peptidases. Cells make it in two ATP-dependent steps: gamma-glutamylcysteine synthetase joins glutamate and cysteine, then glutathione synthetase adds glycine. The pathway is feedback-inhibited by glutathione itself, so intracellular levels tend to stay within a narrow range. Because cysteine is often limiting, sulfur amino acid supply influences how much glutathione a cell can produce.
In its reduced form, glutathione carries a sulfhydryl group that can donate electrons. This property lets it act as a major cellular antioxidant and redox buffer. Glutathione peroxidase uses it to reduce hydrogen peroxide and lipid peroxides, while glutathione reductase regenerates the reduced form using NADPH. The ratio of reduced glutathione to glutathione disulfide is widely used as an indicator of oxidative stress, though the ratio changes with compartment, cell type, and sample handling. Oxidized glutathione can also form mixed disulfides with proteins, affecting their activity.
Synthesis occurs in two ATP-dependent steps. The enzyme glutamate-cysteine ligase joins glutamate and cysteine to form gamma-glutamylcysteine, and glutathione synthetase adds glycine. The first step is rate-limiting and is influenced by cysteine availability and feedback inhibition by GSH. Breakdown involves gamma-glutamyl transferase and subsequent peptidases, which release constituent amino acids for reuse. Because turnover differs among tissues, measurements from blood, plasma, and tissues are not directly interchangeable. Research continues to clarify how compartment-specific pools are regulated in health and disease.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. It contains an unusual gamma-glutamyl bond between glutamate and cysteine, which resists cleavage by many peptidases. The reduced form, GSH, carries a thiol group on cysteine and is the dominant intracellular form in most cells. Its structure allows it to participate in redox reactions and to serve as a sulfur donor. The oxidized form, GSSG, consists of two GSH molecules joined by a disulfide bond.
== Early life, education and career == Moroder studied chemistry at the University of Padova, where he graduated 1965 in chemistry with the doctoral thesis on synthesis of S-peptide of ribonuclease A in the laboratory of Ernesto Scoffone at the Institute of Organic Chemistry. In 1968 he joined Klaus H. Hofmann's Group at the University of Pittsburgh to work on chemical synthesis of the peptidic adrenocorticotropic hormone and its derivatives. Moroder habilitated in 1971 at the University of Padova in Chemistry of Natural Products. 1975 he became a senior research fellow in the Department of Peptide Chemistry at the Max Planck Institute for Biochemistry (MPIB) in Martinsried headed by Erich Wünsch. Between 1991 and 2008 he was the head of the Laboratory of Bioorganic chemistry at the MPIB. Since 1994 he was an adjunct professor at the Technical University of Munich.
Press release describing discovery of Osedax BBC website – link to story about discovery of Osedax worms in the North Sea A Motley Collection of Boneworms – Monterey Bay Aquarium Research Institute Discovered in the deep: the worm that eats bones – The Guardian
Hemoglobin H disease, also called α-thalassemia intermedia, is a disease affecting hemoglobin, the oxygen carrying molecule within red blood cells. It is a form of α-thalassemia which most commonly occurs due to deletion of 3 out of 4 of the α-globin genes.
Sources: en.wikipedia.org
=== Treating vitamin deficiency in newborns === Vitamin K1 is given as an injection to newborns to prevent vitamin K deficiency bleeding. The blood clotting factors of newborn babies are roughly 30–60% that of adult values; this appears to be a consequence of poor transfer of the vitamin across the placenta, and thus low fetal plasma vitamin K. Occurrence of vitamin K deficiency bleeding in the first week of the infant's life is estimated at between 1 in 60 and 1 in 250. Human milk contains 0.85–9.2 μg/L (median 2.5 μg/L) of vitamin K1, while infant formula is formulated in range of 24–175 μg/L. Late onset bleeding, with onset 2 to 12 weeks after birth, can be a consequence of exclusive breastfeeding, especially if there was no preventive treatment. Late onset prevalence reported at 35 cases per 100,000 live births in infants who had not received prophylaxis at or shortly after birth. Vitamin K deficiency bleeding occurs more frequently in the Asian population compared to the Caucasian population. Bleeding in infants due to vitamin K deficiency can be severe, leading to hospitalization, brain damage, and death. Intramuscular injection, typically given shortly after birth, is more effective in preventing vitamin K deficiency bleeding than oral administration, which calls for weekly dosing up to three months of age.
Based on a White supremacy campaign that returned Democrats to dominance, in 1900 the state legislature passed a new constitution, with a suffrage amendment that raised barriers to voter registration, resulting in the disenfranchisement of most Black citizens and many poor White citizens. Loss of the ability to vote also disqualified Black men (and later women) from sitting on juries and serving in any office—local, state or federal. The rising Black middle-class in Raleigh and other areas was politically silenced and shut out of local governance, and the Republican Party was no longer competitive in the state. It was not until after federal civil rights legislation was passed in the mid-1960s that the majority of Black citizens in North Carolina would again be able to vote, sit on juries and serve in local offices. By that time, many African Americans had left the state in the Great Migration to northern industrial cities for more opportunities. No African American was elected to Congress from North Carolina until 1992.
== Prolactin == Agonists: Growth hormone Human placental lactogen Placental growth hormone (growth hormone variant) Prolactin S179D-hPRL Somatotropin Antagonists: Δ1–9-G129R-hPRL Δ1–14-G129R-hPRL G120K-hGH G129R-hPRL Prolactin modulators: Prolactin inhibitors: D2 receptor agonists (e.g., bromocriptine, cabergoline); Prolactin releasers: D2 receptor antagonists (e.g., domperidone, metoclopramide, risperidone) Estrogens (e.g., estradiol) Progestogens (e.g., progesterone)
Sources: en.wikipedia.org
=== INCB Yellow List === This document contains the current list of narcotic drugs under international control and additional information to assist governments in filling in the International Narcotics Control Board questionnaires related to narcotic drugs, namely, form A, form B and form C. In medicine, a chemical agent that induces stupor, coma, or insensibility to pain (also called narcotic analgesic). In the context of international drug control, "narcotic drug" means any drug defined as such under the 1961 Convention.
In the United Kingdom, the varicella vaccine has been added in 2026 to the routine children vaccination, combined with the MMR vaccine, at ages 12 and 18 months. Since 2013, the MMRV vaccine has been offered for free to all Brazilian citizens. Other countries, such as France, have targeted recommendations for the vaccine, e.g. for children over 12 years who have not yet been infected with varicella.
=== Sales === The Xbox 360 version was the third best-selling game of August 2007, with 490,900 copies. The Wall Street Journal reported that shares in Take-Two Interactive "soared nearly 20%" in the week following overwhelmingly favorable early reviews of the game. Take-Two Interactive announced that by June 5, 2008, over 2.2 million copies of BioShock had been shipped. In a June 10, 2008 interview, Roy Taylor, Nvidia's VP of Content Business Development, stated that the PC version has sold over one million copies. According to Take-Two Interactive's chairman Strauss Zelnick, the game had sold around 3 million copies by June 2009. By March 2010, BioShock had sold 4 million copies, with the release of its sequel, BioShock 2, boosting sales of the original game.
=== Yeast === Yeast is a single cell, fungal organism widely found in nature and plays important roles in various biological processes. Some species of yeast, such as Gluconacetobacter xylinus, are capable of producing cellulose through fermentation. This cultivation depends on the temperature, moisture and pH of the media. During fermentation, the yeast produces cellulose as an extracellular matrix, forming a dense network of cellulose fibers. This microbial cellulose can then be harvested, purified, and processed into textile fibers. This process is not consistent for most species of yeast though. The microbial cellulose produced by most yeast species can be processed into textile fibers after being reinforced with other natural or synthetic fibers using techniques such as spinning, weaving, or knitting. Depending on the desired characteristics, properties such as strength, softness, or moisture absorption can be controlled. The resulting textile materials can be used to produce a variety of products, including apparel, home textiles, and technical textiles. Using yeast in the biotextile industry contains many environmentally friendly and cost effective perks. Yeast fermentation can be carried out using renewable feedstocks such as agricultural residues, waste streams, or plant-based sugars, reducing reliance on finite resources and minimizing environmental impact. Additionally, microbial cellulose production is highly efficient, with relatively low energy and water requirements compared to conventional textile manufacturing processes.
Sources: en.wikipedia.org
GSH is the reduced thiol form, while GSSG is the disulfide-linked oxidized dimer. The GSH:GSSG ratio is used as a redox indicator, though the ratio can vary with sample handling and cell type.
Glutathione is present in many foods, including meats, poultry, fish, some vegetables, and fruits. Cooking, storage, and digestion affect the amounts available for absorption.
Yes, both enzymatic steps in glutathione synthesis consume ATP. The first step, catalyzed by glutamate-cysteine ligase, is usually rate-limiting.
Glutathione is a tripeptide made from glutamate, cysteine, and glycine. Its cysteine residue provides a thiol group that is central to its redox activity. The glutamate-cysteine bond forms through the gamma-carboxyl group of glutamate.