This is a working overview of GSSG, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-12-07. Anything still debated is marked as such rather than presented as settled.
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.
Several analytical methods can quantify glutathione, including high-performance liquid chromatography (HPLC) with UV or fluorescence detection for separating GSH and GSSG. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) offers higher specificity and sensitivity, often detecting nanomolar concentrations. The enzymatic recycling assay, often called the Tietze method, measures total glutathione by coupling reduction of GSSG to a colorimetric or fluorometric readout. Capillary electrophoresis and electrochemical detection are also used in specialized laboratories. Each method has distinct advantages and limitations regarding throughput, cost, and susceptibility to interference.
Interpreting glutathione measurements requires attention to pre-analytical variables. The GSSG concentration in a sample can rise artificially during storage or processing, making the GSH/GSSG ratio unreliable if not controlled. Reference ranges vary by specimen type, assay, and population, so comparisons across studies are difficult. Plasma glutathione is low and sensitive to hemolysis, while whole blood reflects primarily erythrocyte content. Many studies measure total glutathione rather than the reduced and oxidized forms separately, which limits conclusions about redox status.
Accurate measurement of glutathione begins with careful sample handling. Because GSH oxidizes rapidly to GSSG, samples must be processed quickly or frozen immediately. Acid precipitation with metaphosphoric acid or perchloric acid is common; it lowers pH, precipitates proteins, and helps preserve the reduced form. Chelating agents such as EDTA can limit metal-catalyzed oxidation. For whole blood, hemolysis releases glutathione from erythrocytes, so plasma and serum values differ substantially from whole blood values.
| 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 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.
Glutathione is present in most tissues, with especially high concentrations in the liver. It also serves as a cofactor for some enzymes and helps transport amino acids across cell membranes. In plants and microorganisms, glutathione contributes to stress responses and metal handling. The molecule is synthesized in two ATP-dependent steps, first producing gamma-glutamylcysteine and then adding glycine. Because cysteine availability often limits synthesis, dietary and metabolic factors can influence glutathione levels. Research continues to examine how these levels relate to health and disease.
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.
Glutathione supports several cellular processes beyond direct antioxidant action. It serves as a cofactor for glutathione peroxidase and glutathione S-transferase enzymes, which reduce peroxides and conjugate electrophiles, respectively. The molecule also acts as a reservoir of cysteine, an amino acid that can limit protein synthesis and redox signaling. In human nutrition, oral glutathione is sold as a supplement, but how much intact glutathione reaches tissues after ingestion remains an active research question. Clinical claims about supplementation are not uniformly supported by controlled trials.
Glutathione is a small tripeptide built from glutamic acid, cysteine, and glycine. Its peptide bond between glutamate and cysteine involves the gamma-carboxyl group rather than the usual alpha-carboxyl group. This structure gives the molecule a reactive thiol on the cysteine residue. The reduced form, often abbreviated GSH, is the predominant intracellular species in many cell types. Because the thiol can donate electrons, glutathione participates in redox chemistry and in the conjugation of reactive molecules.
Cells synthesize glutathione through two ATP-dependent steps: glutamate-cysteine ligase joins glutamate and cysteine, and glutathione synthetase adds glycine to form the complete tripeptide. Breakdown occurs through gamma-glutamyl transpeptidase and subsequent peptidase reactions, forming the gamma-glutamyl cycle. Within cells, glutathione also forms a disulfide-linked dimer called GSSG when two GSH molecules react. The balance between GSH and GSSG is widely used as an indicator of oxidative conditions, although the ratio can vary by compartment and tissue.
While Marco Polo wrote of Mongolian Tatar troops in the time of Kublai Khan who carried sun-dried skimmed milk as "a kind of paste", the first modern production process for dried milk was invented by the Russian doctor Osip Krichevsky in 1802. The first commercial production of dried milk was organized by the Russian chemist M. Dirchoff in 1832. In 1855, T. S. Grimwade took a patent on a dried milk procedure, though William Newton had patented a vacuum drying process as early as 1837. In modern times, powdered milk is usually made by spray drying nonfat skimmed milk, whole milk, buttermilk or whey. Pasteurized milk is first concentrated in an evaporator to approximately 50 percent milk solids. The resulting concentrated milk is then sprayed into a heated chamber where the water almost instantly evaporates, leaving fine particles of powdered milk solids. Alternatively, the milk can be dried by drum drying. Milk is applied as a thin film to the surface of a heated drum, and the dried milk solids are then scraped off. However, powdered milk made this way tends to have a cooked flavour, due to caramelization caused by greater heat exposure. Another process is freeze drying, which preserves many nutrients in milk, compared to drum drying. The drying method and the heat treatment of the milk as it is processed alters the properties of the milk powder, such as its solubility in cold water, its flavour, and its bulk density.
==== Moxibustion and cupping ==== Four adverse events associated with moxibustion were bruising, burns and cellulitis, spinal epidural abscess, and large superficial basal cell carcinoma. Ten adverse events were associated with cupping. The minor ones were keloid scarring, burns, and bullae; the serious ones were acquired hemophilia A, stroke following cupping on the back and neck, factitious panniculitis, reversible cardiac hypertrophy, and iron deficiency anemia.
== Mutation screening == DHPLC is widely used as a high-throughput mutation-screening method in both research and diagnostic applications, but samples with altered chromatographic patterns generally still require follow-up DNA sequencing to identify the exact variant. Early reports highlighted automated instrumentation, analyses of about 5 minutes per sample, and the ability to analyze PCR fragments up to 1.5 kb.
The French explorer and Acadia's first historian Marc Lescarbot described Jerusalem artichokes as being "as big as turnips or truffles," suitable for eating and taste "like chards, but more pleasant." In 1629, the English herbalist and botanist John Parkinson wrote that the widely grown Jerusalem artichoke had become very common and cheap in London, so much so "that even the most vulgar begin to despise them." In contrast, when they had first arrived in England, the tubers had been "dainties for the Queen." Lewis and Clark ate the tubers, prepared by an indigenous woman, in modern-day North Dakota. They have also been called the "Canadian truffle".
Sources: en.wikipedia.org
Australia's first federal labour rights followed the Constitution of Australia in 1901, yet the law had long regulated work in colonies, often violently suppressing labour freedom. The land of Australia was forcibly settled by British Empire migrants, who anchored in Botany Bay and then declared they held possession of the eastern continent in 1780. After losing territory to the United States in the American War of Independence, Britain established a penal colony of 1400 settlers and convicts in Sydney in 1788. Before colonisation, there were around 1.2 million Indigenous Australians, but contact with European settlers killed up to 80% of people through smallpox and other diseases. In the Australian frontier wars over the next century, around 115,000 Indigenous people were massacred or killed, particularly in Queensland. Indigenous Australian labour was typically organised on hunter-gathering lines, and was cooperative within and between tribes, and through trade among national groups. By contrast, British labour was primarily forced, with a constant supply of prisoners from the British Isles whose crimes were often related to poverty or trying to seek better wages. For example, in R v Lovelass a group of five farm workers in Tolpuddle, Dorset had organised a trade union, because their wages were cut from nine shillings to a starvation wage of six shillings a week. They were convicted under the Unlawful Oaths Act 1797 and Unlawful Societies Act 1799 and sentenced to transportation to Sydney.
=== Bombay blood === Also known as hh blood group, this rare blood type cannot receive blood from any of the ABO blood group, and must receive hh blood from either another person with this condition or themselves (autologous transfusions).
CMT can also be produced by X-linked mutations, in which case it is called X-linked CMT (CMTX). In CMTX, mutated connexons create nonfunctional gap junctions that interrupt molecular exchange and signal transport. The mutation can appear in the GJB1 gene coding for the connexin 32 protein, a gap junction protein expressed in Schwann cells. Because this protein is also present in oligodendrocytes, demyelination can appear in the CNS as well. Schwann cells create the myelin sheath by wrapping their plasma membranes around the axon. These Schwann cells work together with neurons and fibroblasts to create a functional nerve. Schwann cells and neurons exchange molecular signals by way of gap junctions that regulate survival and differentiation. Demyelinating Schwann cells cause abnormal axon structure and function. They may cause axon degeneration, or they may simply cause axons to malfunction. The myelin sheath allows nerve cells to conduct signals faster. When the myelin sheath is damaged, however, nerve signals are slower. This can be measured by a common neurological test, electromyography. When the axon is damaged, the result is a reduced compound muscle action potential.
On 19 June, Afghanistan launched airstrikes inside Pakistan claiming that the camps targeted were used by terror groups like the ISIS-K and "hostile intelligence circles" that collaborated and planned attacks inside Afghanistan. Pakistan denied such strikes had taken place on any camps and instead claimed to have downed an intruding drone. An insurgent was killed following a drone strike on a security post in Lakki Marwat, which wounded three police personnel. Afghan Taliban announced the creation of a new 8,000 strong "Hibati" special unit to be deployed at the border against Pakistan, of which 4,000 were already deployed. On 20 June, two engagements occurred between police and insurgents in Lakki Marwat District. Hathikhel tribal lashkar captured three family members of a TTP insurgent in Bannu District, accusing them of being Taliban collaborators. TTP captured an FC soldier from Kohat District, later releasing him on condition of resignment. Sindh Rangers captured a TTP militant from Karachi. A policeman was injured in a TTP grenade attack on a police post in Tank District. Two TTP IuM insurgents were killed in a military operation in North Waziristan. An operation against a TTP commander was initiated in South Waziristan. Twin bomb blasts in Bannu killed seven civilians and wounded three. TTP "intelligence" claimed to have assassinated a Pakistani intelligence collaborator in Quetta. On 21 June, CTD captured a trained TTP suicide bomber from Karachi. A police station in Lakki Marwat District was targeted by a quadcopter drone strike.
Cytochromes c (cyt c, c-type cytochromes) cytochromes, or heme-containing proteins, that have heme C covalently attached to the peptide backbone via one or two thioether bonds. These bonds are in most cases part of a specific Cys-X-X-Cys-His (CXXCH) binding motif, where X denotes a miscellaneous amino acid. Two thioether bonds of cysteine residues bind to the vinyl sidechains of heme, and the histidine residue coordinates one axial binding site of the heme iron. Less common binding motifs can include a single thioether linkage, a lysine or a methionine instead of the axial histidine or a CXnCH binding motif with n>2. The second axial site of the iron can be coordinated by amino acids of the protein, substrate molecules or water. Cytochromes c possess a wide range of properties and function as electron transfer proteins or catalyse chemical reactions involving redox processes. A prominent member of this family is mitochondrial cytochrome c.
Sources: en.wikipedia.org
== Clinical trials == On 7 March 2024, the company announced the results from the Phase I trial of the pill form of amycretin. In January 2025, the company announced the results of its 1B/2A trial. The trial investigated safety, tolerability, and pharmacokinetics following weekly subcutaneous administration in 125 patients. Treatment duration was up to 36 weeks. Novo Nordisk Chief Executive Lars Fruergaard Jørgensen forecast the roll-out of amycretin to be largely injectable medicines at first with oral versions being introduced later in higher-priced markets.
Haüy's theory was generally accepted by his fellow mineralogists in the period 1801–1815 but then came under attack from the German dynamist school led by Christian Samuel Weiss. Weiss and his followers studied the external symmetry of crystals rather than their internal structure. In 1819, Weiss demonstrated the generality of the phenomenon of hemihedry (half of the vertices/edges/faces of a crystal act differently from the other half), thus challenging Haüy's holohedral approach (all vertices/edges/faces of a crystal act in the same manner). Haüy's crystal structure theory was criticised as over-simplistic by William Hyde Wollaston in 1809 and by Henry James Brooke in 1819. Haüy also tended to ignore experimental results that contradicted his structural theory, such as those achieved with the more accurate reflection goniometer invented by Wollaston in 1809. In 1813 Wollaston adopted Dalton's ideas and proposed using sphere packing to model crystal structures. In 1814 André-Marie Ampère published a theory of the chemical combination of substances, based on Haüy's polyhedral forms. However, Ampère's work had little impact on contemporary chemists. In 1819 David Brewster classified crystals according to their optical properties, as isotropic, uniaxial, or biaxial. In a paper published in 1830 Brewster attempted to relate the phenomenon of double refraction to the arrangement of the molecules in crystals.
=== 31 March === The International Monetary Fund approved a $15.6 billion support package for Ukraine to assist with the country's economic recovery. The package would be the first of its kind for a country at war. The World Bank estimated that around US$411 billion was needed for Ukraine's recovery and for rebuilding from the invasion.
Loss of E-cadherin is considered to be a fundamental event in EMT. Many transcription factors (TFs) that can repress E-cadherin directly or indirectly can be considered as EMT-TF (EMT inducing TFs). SNAI1/Snail 1, SNAI2/Snail 2 (also known as Slug), ZEB1, ZEB2, TCF3 and KLF8 (Kruppel-like factor 8) can bind to the E-cadherin promoter and repress its transcription, whereas factors such as Twist, Goosecoid, TCF4 (also known as E2.2), homeobox protein SIX1 and FOXC2 (fork-head box protein C2) repress E-cadherin indirectly. SNAIL and ZEB factors bind to E-box consensus sequences on the promoter region, while KLF8 binds to promoter through GT boxes. These EMT-TFs not only directly repress E-cadherin, but also repress transcriptionally other junctional proteins, including claudins and desmosomes, thus facilitating EMT. On the other hand, transcription factors such as grainyhead-like protein 2 homologue (GRHL2), and ETS-related transcription factors ELF3 and ELF5 are downregulated during EMT and are found to actively drive MET when overexpressed in mesenchymal cells. Since EMT in cancer progression recaptures EMT in developmental programs, many of the EMT-TFs are involved in promoting metastatic events. Several signaling pathways (TGF-β, FGF, EGF, HGF, Wnt/beta-catenin and Notch) and hypoxia may induce EMT. In particular, Ras-MAPK has been shown to activate Snail and Slug. Slug triggers the steps of desmosomal disruption, cell spreading, and partial separation at cell–cell borders, which comprise the first and necessary phase of the EMT process.
Official website The Jesus and Mary Chain at AllMusic The Jesus and Mary Chain at IMDb 1985 audio interview on RPM Club Long article in The Guardian, 2014 The Making of Psychocandy, 2015 interview with Jim Reid The Jesus and Mary Chain's Psychocandy, 2016 article on The Literary Hub The Jesus And Mary Chain's Glasgow Eyes, 2024 interview with Jim Reid on Qobuz Magazine
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 oxidizes quickly when cells are disrupted or when samples sit at room temperature. Rapid processing or immediate freezing minimizes the conversion of GSH to GSSG. This step helps ensure that the measured ratio reflects the original biological state.