This is a working overview of thiol, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-01-18 and is reviewed periodically as new material appears.
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.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Common analytical method | LC-MS/MS or HPLC | Separation of GSH and GSSG |
| Limit of detection | Nanomolar range | Method dependent |
| Typical sample storage | -80 °C | For biological matrices |
| Common reducing agent | TCEP or DTT | Prevents oxidation during processing |
| Common synonym | Gamma-glutamylcysteinylglycine | Systematic name |
Functionally, glutathione supports redox balance by donating electrons and becoming oxidized. It also serves as a cofactor for enzymes such as glutathione peroxidases and glutathione S-transferases. These enzymes participate in peroxide reduction and in conjugation reactions that help process reactive molecules. Separate from antioxidant roles, glutathione can modify protein cysteines through S-glutathionylation, influencing enzyme activity and signaling. Research continues to examine how these chemical roles translate into whole-organism effects.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. Its glutamate-cysteine linkage uses the gamma-carboxyl group of glutamate, a feature that resists standard peptidases. The cysteine residue provides a thiol group, which gives the molecule its reducing character. In cells, glutathione is often the most abundant small-molecule thiol, with concentrations varying widely by tissue and compartment. It exists mainly in a reduced form called GSH, while oxidation produces a disulfide-linked dimer called GSSG.
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.
Sean Kinney said about the band's reunion: I never called Jerry; he never called me, and said, 'Hey, let's get the band back together,' you know? We had been taking every step extremely cautious and slow, and just doing whatever feels right: If it's genuine and we're doing it for genuine reasons and we're all okay with it then we take a little step. None of us is broke. Nobody needs to be a rock dork, and you know, stroke their ego. I mean, we don't really operate like that. So as long as it felt good and from the right place and it's about making music and carrying on... About the pressure being put on DuVall for replacing Staley as lead vocalist, Cantrell said, To put all that weight on Will's shoulders is unfair. We're just figuring out how we work as a team. Although the band has changed, we've lost Layne, we've added Will, and there was no master plan. Playing again in 2005 felt right, so we did the next thing and toured. We did it step by step. It's more than just making music, and it always has been. We've been friends a long time. We've been more of a family than most, and it had to be okay from here [pointing to his heart]. Former The Doors manager Bill Siddons and his management company, Core Entertainment, co-managed Alice in Chains with original manager Susan Silver from 2005 to 2007. The band started writing and demoing songs for a new album with DuVall in April 2007. But the band did not show further signs of progress until October 2008, when they announced that they had begun recording with producer Nick Raskulinecz in the studio.
It is usually served either with a sweet ginger syrup, or a mushroom gravy called da lu (打卤). It is normally coagulated at the restaurant into a serving container. Douhua is not always considered a type of tofu, but rather a type of food in its own right. Some variation exists among soft tofus. Black douhua (黑豆花, hēidòuhuā) is a type of silken tofu made from black soybeans, which is usually made into dòuhuā (豆花) rather than firm or dry tofu. The texture of black bean tofu is slightly more gelatinous than regular douhua and the color is greyish in tone. This type of tofu is eaten for its earthy "black bean taste". Edamame tofu is a Japanese variety of kinugoshi tōfu made from edamame (fresh green soybeans); it is pale green in color and often studded with whole edamame.
===== MeSH D08.811.913.555 – one-carbon group transferases (EC 2.1) ===== MeSH D08.811.913.555.150 – amidinotransferases MeSH D08.811.913.555.275 – carboxyl and carbamoyl transferases MeSH D08.811.913.555.275.200 – aspartate carbamoyltransferase MeSH D08.811.913.555.275.600 – ornithine carbamoyltransferase MeSH D08.811.913.555.400 – hydroxymethyl and formyl transferases MeSH D08.811.913.555.400.100 – aminomethyltransferase MeSH D08.811.913.555.400.300 – glutamate formimidoyltransferase MeSH D08.811.913.555.400.500 – glycine hydroxymethyltransferase MeSH D08.811.913.555.400.625 – phosphoribosylaminoimidazolecarboxamide formyltransferase MeSH D08.811.913.555.400.750 – phosphoribosylglycinamide formyltransferase MeSH D08.811.913.555.500 – methyltransferases MeSH D08.811.913.555.500.100 – acetylserotonin n-methyltransferase MeSH D08.811.913.555.500.175 – betaine-homocysteine S-methyltransferase MeSH D08.811.913.555.500.250 – catechol O-methyltransferase MeSH D08.811.913.555.500.350 – dna modification methylases MeSH D08.811.913.555.500.350.500 – dna (cytosine-5-)-methyltransferase MeSH D08.811.913.555.500.350.700 – site-specific dna-methyltransferase (adenine-specific) MeSH D08.811.913.555.500.350.850 – site-specific dna methyltransferase (cytosine-specific) MeSH D08.811.913.555.500.387 – glycine N-methyltransferase MeSH D08.811.913.555.500.425 – guanidinoacetate N-methyltransferase MeSH D08.811.913.555.500.500 – histamine N-methyltransferase MeSH D08.811.913.555.500.625 – homocysteine S-methyltransferase MeSH D08.811.913.555.500.645 – 5-methyltetrahydrofolate-homocysteine s-methyltransferase MeSH D08.811.913.555.500.650 – nicotinamide N-methyltransferase MeSH D08.811.913.555.500.700 – phenylethanolamine N-methyltransferase MeSH D08.811.913.555.500.710 – phosphatidyl-N-methylethanolamine N-methyltransferase MeSH D08.811.913.555.500.712 – phosphatidylethanolamine N-methyltransferase MeSH D08.811.913.555.500.800 – protein methyltransferases MeSH D08.811.913.555.500.800.400 – histone-lysine n-methyltransferase MeSH D08.811.913.555.500.800.650 – o-6-methylguanine-DNA methyltransferase MeSH D08.811.913.555.500.800.750 – protein-arginine n-methyltransferase MeSH D08.811.913.555.500.800.800 – protein o-methyltransferase MeSH D08.811.913.555.500.800.800.700 – protein d-aspartate-l-isoaspartate methyltransferase MeSH D08.811.913.555.500.862 – thymidylate synthase MeSH D08.811.913.555.500.925 – trna methyltransferases
On 12 September 2024, Paetongtarn Shinawatra and the Cabinet presented their policy statement to Parliament, outlining ten priority policies for immediate implementation. These included comprehensive debt restructuring, measures to support Thai entrepreneurs, reductions in energy and utility costs, and efforts to integrate the informal and underground economies into the tax system. Additional priorities included economic stimulus through digital wallets, modernization of the agricultural sector, tourism promotion, anti-narcotics initiatives, crime prevention, and enhancements to social welfare, particularly for vulnerable groups, stateless individuals, and ethnic minorities. Following the policy announcement, on 13 September 2024, Paetongtarn and relevant Cabinet members visited Mae Sai district, Chiang Rai, to assess the flood situation in northern Thailand.
Sources: en.wikipedia.org
antiparallel The contrasting orientations of the two strands of a double-stranded nucleic acid (and more generally any pair of biopolymers) which are parallel to each other but with opposite directionality. For example, the two complementary strands of a DNA molecule run side-by-side but in opposite directions with respect to chemical numbering conventions, with one strand oriented 5'-to-3' and the other 3'-to-5'.
== Chemical mechanism == The carbonyl group of the sugar reacts with the amino group of the amino acid, producing N-substituted glycosylamine and water The unstable glycosylamine undergoes Amadori rearrangement, forming ketosamines Several ways are known for the ketosamines to react further: Produce two water molecules and reductones Diacetyl, pyruvaldehyde, and other short-chain hydrolytic fission products can be formed. Produce brown nitrogenous polymers and melanoidins
Bowery Poetry is a performance space at Bowery and Bleecker Street. It was founded in 2001 as Bowery Poetry Club (BPC), and provided a home base for established and upcoming artists. It was founded by Bob Holman, owner of the building and former Nuyorican Poets Café Poetry Slam MC (1988–1996). The BPC featured regular shows by Amiri Baraka, Anne Waldman, Taylor Mead, Taylor Mali, along with open mic, gay poets, a weekly poetry slam, and an Emily Dickinson Marathon, amongst other events. The club closed in 2012 and reopened in 2013 as a shared performance space under the name "Bowery Poetry". Bowery Arts + Science presents poetry, and Duane Park presents alternative burlesque in this space.
==== Pneumofathometer ==== A pneumofathometer is a device used to measure the depth of a diver by displaying the back-pressure on a gas supply hose with an open end at the diver, and a flow rate with negligible resistance in the hose. The pressure indicated is the hydrostic pressure at the depth of the open end, and is usually displayed in units of metres or feet of seawater, the same units used for decompression calculations. The pneumo line is usually a 0.25 inches (6.4 mm) bore hose in the diver's umbilical, supplied with breathing gas from the gas panel via a supply valve. Downstream from the valve there is a branch to a high resolution pressure gauge, a restriction to flow to the gauge, and an overpressure relief valve to protect the gauge from full panel supply pressure in case the pneumo line is used for emergency breathing gas supply. Each diver has an independent pneumofathometer, and if there is a bell, it will also have an independent pneumofathometer.
=== Agriculture === Ectomycorrhizal fungi are not prominent in agricultural and horticultural systems. Most of the economically relevant crop plants that form mycorrhizas tend to form them with arbuscular mycorrhizal fungi. Many modern agricultural practices such as tillage, heavy fertilizers and fungicides are extremely detrimental to mycorrhizas and the surrounding ecosystem. It is possible that agriculture indirectly affects nearby ectomycorrhizal species and habitats; for example, increased fertilization decreases sporocarp production.
Sources: en.wikipedia.org
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.
The Tietze assay is an enzymatic recycling method that measures total glutathione. It uses glutathione reductase to reduce GSSG back to GSH, which then reacts with a chromogen or fluorophore. The reaction cycles repeatedly, amplifying the signal for detection.
Yes, but the choice of blood fraction matters. Plasma or serum contains low glutathione levels and is easily affected by hemolysis. Whole blood mainly reflects the high glutathione content of erythrocytes, so results from different fractions are not directly comparable.
It is a tripeptide of glutamic acid, cysteine, and glycine. The linkage between glutamate and cysteine uses the gamma-carboxyl group, which is unusual for peptides.