Everything below concerns derivatization. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-10-13. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Measuring glutathione in biological samples requires attention to oxidation and matrix effects. High-performance liquid chromatography with ultraviolet or fluorescence detection can separate reduced and oxidized forms after derivatization. Liquid chromatography with tandem mass spectrometry offers higher specificity and can quantify glutathione alongside related thiols. Because glutathione can oxidize during sample handling, many protocols use rapid acidification with metaphosphoric acid or sulfosalicylic acid. Internal standards help correct for losses during extraction and analysis.
Enzymatic recycling assays provide a complementary approach for total glutathione. In these methods, glutathione reductase reduces oxidized glutathione while a thiol-reactive reagent, such as 5,5'-dithiobis(2-nitrobenzoic acid), produces a colored product. The reaction cycles between reduced and oxidized forms, amplifying the signal. Spectrophotometric or fluorometric detection can then estimate concentration. Distinguishing reduced glutathione from glutathione disulfide often requires separate aliquots, masking agents, or chromatographic separation, and the choice affects reported values.
Storage conditions strongly influence glutathione stability. The solid reduced form is commonly kept desiccated at or below minus twenty degrees Celsius, protected from light and moisture. Aqueous solutions are less stable because the thiol group reacts with dissolved oxygen, and oxidation accelerates at neutral or alkaline pH. Acidic solutions and oxygen-free handling can slow degradation, but repeated freeze-thaw cycles should be avoided. Researchers often verify concentration before use, because apparent losses can arise from oxidation or water uptake.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C10H17N3O6S | Tripeptide of glutamate, cysteine, and glycine. |
| Molar mass | 307.32 g/mol | Calculated from the molecular formula. |
| Appearance | White to off-white powder | Typically crystalline or lyophilized solid. |
| Solubility | Soluble in water; insoluble in ethanol | Aqueous solutions are acidic and prone to oxidation. |
| Typical storage | -20 °C, desiccated, protect from light | Reduce exposure to oxygen and moisture. |
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 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.
Measuring glutathione requires attention to oxidation during sample handling, because GSH in biological samples can convert to GSSG or form mixed disulfides with proteins after collection. Acidic extraction, rapid cooling, and chelating agents are commonly used to limit such changes. Analytical methods usually distinguish free reduced glutathione, total glutathione, and protein-bound forms. Because these forms have different stability and reactivity, reported values depend heavily on the preparation protocol. No single preparation is universally suitable for every biological matrix or analytical goal.
Several techniques are used for quantification. Enzymatic recycling assays rely on glutathione reductase and a colorimetric or fluorescent readout, offering sensitivity for total glutathione. High-performance liquid chromatography can separate GSH from GSSG and other thiols, often with UV, fluorescence, or electrochemical detection. Mass spectrometry provides structural confirmation and can quantify low-abundance species when paired with separation. Each approach has trade-offs in specificity, throughput, and equipment requirements, so method selection depends on the research question and available instrumentation.
The March of the Chinese People's Liberation Army was adopted as the military anthem by the Central Military Commission on 25 July 1988. The lyrics of the anthem were written by composer Gong Mu (real name: Zhang Yongnian; Chinese: 张永年) and the music was composed by Korea-born Chinese composer Zheng Lücheng.
A comparative genomic study (in 2020) analyzed 494 complete genomes from the Pseudomonas genus, of which 189 were P. aeruginosa strains. The study observed that their protein count and GC content ranged between 5500 and 7352 (average: 6192) and between 65.6 and 66.9% (average: 66.1%), respectively. This comparative analysis further identified 1811 aeruginosa-core proteins, which accounts for more than 30% of the proteome. The higher percentage of aeruginosa-core proteins in this latter analysis could partly be attributed to the use of complete genomes. Although P. aeruginosa is a very well-defined monophyletic species, phylogenomically and in terms of ANIm values, it is surprisingly diverse in terms of protein content, thus revealing a very dynamic accessory proteome, in accordance with several analyses. It appears that, on average, industrial strains have the largest genomes, followed by environmental strains, and then clinical isolates. The same comparative study (494 Pseudomonas strains, of which 189 are P. aeruginosa) identified that 41 of the 1811 P. aeruginosa core proteins were present only in this species and not in any other member of the genus, with 26 (of the 41) being annotated as hypothetical. Furthermore, another 19 orthologous protein groups are present in at least 188/189 P. aeruginosa strains and absent in all the other strains of the genus.
The bite is immediately followed by the local pain of a burning character; the limb soon swells and becomes discolored, and within one to three hours great prostration, accompanied by vomiting, and often diarrhea, sets in. Cold, clammy perspiration is usual. The pulse becomes extremely feeble, and slight dyspnoea and restlessness may be seen. In severe cases, which occur mostly in children, the pulse may become imperceptible and the extremities cold; the patient may pass into coma. In from twelve to twenty-four hours these severe constitutional symptoms usually pass off; but in the meantime, the swelling and discoloration have spread enormously. The limb becomes phlegmonous and occasionally suppurates. Within a few days recovery usually occurs somewhat suddenly, but death may result from the severe depression or from the secondary effects of suppuration. That cases of death, in adults as well as in children, are not infrequent in some parts of the Continent is mentioned in the last chapter of this Introduction. The Viperidae differ much among themselves in the toxicity of their venoms. Some, such as the Indian Russell's viper (Daboia russelli) and saw-scaled viper (E. carinatus); the American rattlesnakes (Crotalus spp.), bushmasters (Lachesis spp.), and lanceheads (Bothrops spp.); and the African adders (Bitis spp.), night adders (Causus spp.), and horned vipers (Cerastes spp.), cause fatal results unless a remedy is speedily applied.
Sources: en.wikipedia.org
=== 2010 census === The 2010 United States census counted 8,573 people, 3,002 households, and 2,318 families in the borough. The population density was 4,154.5 per square mile (1,604.1/km2). There were 3,114 housing units at an average density of 1,509.0 per square mile (582.6/km2). The racial makeup was 68.95% (5,911) White, 0.73% (63) Black or African American, 0.03% (3) Native American, 27.64% (2,370) Asian, 0.01% (1) Pacific Islander, 1.07% (92) from other races, and 1.55% (133) from two or more races. Hispanic or Latino of any race were 6.26% (537) of the population. Korean Americans accounted for 17.8% of the population. Of the 3,002 households, 40.5% had children under the age of 18; 66.2% were married couples living together; 7.9% had a female householder with no husband present and 22.8% were non-families. Of all households, 21.1% were made up of individuals and 15.4% had someone living alone who was 65 years of age or older. The average household size was 2.84 and the average family size was 3.32. Same-sex couples headed 7 households in 2010, an increase from the 5 counted in 2000. 26.8% of the population were under the age of 18, 5.4% from 18 to 24, 20.6% from 25 to 44, 29.8% from 45 to 64, and 17.4% who were 65 years of age or older. The median age was 43.7 years. For every 100 females, the population had 88.6 males. For every 100 females ages 18 and older there were 85.7 males.
The integumentary system (skin) is made up of three layers: the outermost epidermis, the dermis and the hypodermis. The epidermis is typically 10 to 30 cells thick; its main function is to provide a waterproof layer. Its outermost cells are constantly lost; its bottommost cells are constantly dividing and pushing upward. The middle layer, the dermis, is 15 to 40 times thicker than the epidermis. The dermis is made up of many components, such as bony structures and blood vessels. The hypodermis is made up of adipose tissue, which stores lipids and provides cushioning and insulation. The thickness of this layer varies widely from species to species; marine mammals require a thick hypodermis (blubber) for insulation, and right whales have the thickest blubber at 20 inches (51 cm). Although other animals have features such as whiskers, feathers, setae, or cilia that superficially resemble it, no animals other than mammals have hair. It is a definitive characteristic of the class, though some mammals have very little.
The maximum recommended daily dose is 10 milligrams per day. Overdoses of alprazolam can be mild to severe depending on the quantity ingested and if other drugs are taken in combination. Alprazolam overdoses cause excess central nervous system (CNS) depression.
Sources: en.wikipedia.org
=== Category:EC 3.13 (act on carbon–sulfur bonds) === EC 3.13.1.1: UDP-sulfoquinovose synthase EC 3.13.1.3: 2'-hydroxybiphenyl-2-sulfinate desulfinase EC 3.13.1.4: 3-sulfinopropanoyl—CoA desulfinase EC 3.13.1.5: Carbon disulfide hydrolase EC 3.13.1.6: (CysO sulfur-carrier protein)-S-L-cysteine hydrolase EC 3.13.1.7: Carbonyl sulfide hydrolase EC 3.13.1.8: S-adenosyl-L-methionine hydrolase (adenosine-forming)
The Valley Library Special Collections at Oregon State University contain the Ava Helen and Linus Pauling Papers, including digitized versions of Pauling's forty-six research notebooks. In 1986, Caltech commemorated Linus Pauling with a symposium and lectureship. The Pauling Lecture series at Caltech began in 1989 with a lecture by Pauling himself. The Caltech Chemistry Department renamed room 22 of Gates Hall the Linus Pauling Lecture Hall, since Pauling spent so much time there. Other places named after Pauling include Pauling Street in Foothill Ranch, California; Linus Pauling Drive in Hercules, California; Linus and Ava Helen Pauling Hall at Soka University of America in Aliso Viejo, California; Linus Pauling Middle School in Corvallis, Oregon; and Pauling Field, a small airfield located in Condon, Oregon, where Pauling spent his youth. There is a psychedelic rock band in Houston, Texas, named The Linus Pauling Quartet. The asteroid 4674 Pauling in the inner asteroid belt, discovered by Eleanor F. Helin, was named after Linus Pauling in 1991, on his 90th birthday. Linus Torvalds, developer of the Linux kernel, and Linus Sebastian, YouTuber known for the technology-oriented channel Linus Tech Tips, are named after Pauling. Nobel laureate Peter Agre has said that Linus Pauling inspired him. In 2010, Pacific Northwest National Laboratory named its distinguished postdoctoral program in his honor, as the Linus Pauling Distinguished Postdoctoral Fellowship Program.
Pulsatile intravenous insulin therapy, sometimes called metabolic activation therapy or cellular activation therapy, describes in a literal sense the intravenous injection of insulin in pulses versus continuous infusions. Injection of insulin in pulses mimics the physiological secretions of insulin by the pancreas into the portal vein which then drains into the liver. In healthy, non-diabetic individuals, pancreatic secretions of insulin correspond to the intake of food. The pancreas will secrete variable amounts of insulin based upon the amount of food consumed (basically speaking, the more food that is consumed, the more insulin the pancreas will secrete) among other factors. Continuous exposure to insulin and glucagon is known to decrease the hormones' metabolic effectiveness on glucose production in humans due to the body developing an increased tolerance to the hormones. Down-regulation at the cellular level may partially explain the decreased action of steady-state levels of insulin, while pulsatile hormone secretion may allow recovery of receptor affinity and numbers for insulin. Intermittent intravenous insulin administration with peaks of insulin concentrations may enhance suppression of gluconeogenesis and reduce hepatic glucose production.
Sources: en.wikipedia.org
GSH is the reduced, thiol-containing form of glutathione, while GSSG is the oxidized disulfide dimer formed when two GSH molecules react. Cells maintain a high GSH-to-GSSG ratio under normal conditions. A shift toward GSSG is often interpreted as oxidative stress, though sample handling can affect the measured ratio.
No. It is a tripeptide made from three amino acids: glutamate, cysteine, and glycine. The gamma-glutamyl bond is unusual and distinguishes it from typical peptide linkages.
Most ingested glutathione is broken down in the gastrointestinal tract into its constituent amino acids. Some formulations may protect it from digestion, but intact absorption and delivery to specific tissues remain uncertain. Research continues on precursors and delivery methods.
Chromatographic methods can separate the two forms before detection. Enzymatic assays often measure total glutathione first and then use a separate procedure to estimate the oxidized fraction. The difference between total and oxidized amounts provides an indirect estimate of the reduced form.