PTMA gene is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-02-04. Where a claim depends on a specific study, the study is described rather than over-claimed.
Thymosin alpha-1 is a synthetic 28-amino-acid peptide whose sequence was first identified in extracts of bovine thymus tissue during the 1970s. The chain carries an acetyl group on its N-terminal serine. Its acidic residue content is high, which produces strong water solubility and an isoelectric point well below neutrality. Material supplied for laboratory and clinical use is manufactured by solid-phase peptide synthesis rather than purified from animal tissue. Different salt forms, such as the acetate, alter the counter-ion content without changing the peptide backbone.
Whether the free 28-residue peptide circulates in human tissue remains debated. The best-documented human source is prothymosin alpha, a larger acidic protein that carries the sequence at its N-terminus. Reports of measurable peptide levels in serum and lymphoid tissue exist, yet some of that signal may come from cross-reacting fragments or from the parent protein. Most reviews therefore treat prothymosin alpha as the established human molecule and describe independent circulation of the small peptide as an unresolved question.
Immunological studies connect the peptide to multiple parts of the immune response. It has been reported to engage Toll-like receptor signaling, to promote dendritic cell maturation, and to influence the balance of T helper cell subsets. Changes in natural killer cell activity and in cytokine release appear in cell culture and animal models. These observations describe broad immunomodulatory behavior rather than a single defined receptor target, and the primary molecular interaction has not been settled.
20世纪70年代，研究者从胸腺提取物中纯化出多种小肽，Tα1是其中被较早表征的一种。最初的制备依赖组织匀浆和层析步骤，产量低且成分复杂。随着固相肽合成技术成熟，实验室和工业界能够生产与天然序列一致的合成版本。合成肽的纯度可达95%以上，并可通过反相高效液相色谱和质谱进行鉴定。这一转变使研究不再依赖动物胸腺来源。
市售的胸腺素α1通常以冻干粉形式提供，溶解后用于注射。其氨基酸组成包括多个酸性残基，因此在中性pH下带负电荷。该肽可溶于水和生理盐水，但在有机溶剂中溶解度有限。储存条件通常为冻干状态下负20摄氏度，溶解后需冷藏并避免反复冻融。常见的同义词包括胸腺肽α1、thymalfasin和Tα1。
| Property | Value | Notes |
|---|---|---|
| Amino acid length | 28 residues | Single chain with an acetylated N-terminus |
| Molecular mass | Approximately 3,108 Da | Small shifts occur with counter-ion and water content |
| Isoelectric point | Around 3.5 | Low value follows from the many acidic residues |
| Parent molecule | N-terminal region of prothymosin alpha | Free circulating form in humans is not firmly established |
| Common synonyms | Thymalfasin; T alpha 1 | Older literature also uses the full spelled-out form |
Overall evidence quality varies considerably. A large share of published reports come from single centers, rely on surrogate immunological markers, or lack adequate control groups. Systematic reviews have highlighted this heterogeneity as a barrier to pooling results. Open questions include which patients, if any, might benefit, what treatment duration is appropriate, and whether any effect is independent of standard care. The peptide is often described as an immune modulator rather than a therapy for one disease, which complicates confirmatory trial design.
Thymosin alpha 1 was identified in 1977 as a component of thymosin fraction 5, a heterogeneous preparation used in early studies of thymic function. Investigators purified the active material and determined its amino acid sequence, which enabled chemical synthesis. Work in the following decades concentrated on T-cell maturation and immune reconstitution in animals and small human cohorts. Early preparations varied in composition, so results from that period are difficult to compare with studies using defined synthetic peptide.
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Findings across trials are mixed; some report changes in selected immune markers, while others find no clear clinical benefit. Many studies are small and define outcomes differently, which limits comparison. Regulatory approval is confined to a few countries, and the compound is not an approved drug in the United States or most of Europe.
The peptide is generated in cells by cleavage of prothymosin alpha, a larger acidic protein encoded by the PTMA gene. Prothymosin alpha is expressed in many tissues, not only in the thymus, and its functions include nuclear roles in chromatin-related processes. The 28-residue fragment corresponds to the N-terminal portion of that precursor. How the cleavage occurs and how the fragment's concentration is regulated remain open questions; circulating amounts are small and difficult to measure reliably with routine assays.
Thymosin alpha 1 is a short peptide first isolated from bovine thymus tissue in the early 1970s during fractionation work aimed at identifying factors that influence T cell development. It belongs to a family of acidic thymic peptides, and the original preparations contained several components that were later separated by chromatography. The compound is now produced synthetically rather than extracted from tissue, which removes batch variability tied to animal sourcing. Researchers describe it as an immunomodulatory peptide because laboratory studies show effects on several cell types of the innate and adaptive immune systems.
Early work on thymic extracts in the 1960s described a heat-stable acidic fraction containing many polypeptides. Separation of that mixture yielded individual components, and thymosin alpha-1 was named as one of them on the basis of assays for T-cell activity. The first preparations came from calf thymus, while subsequent research and clinical material has been chemically synthesized. Nomenclature in older papers is inconsistent, and the same peptide sometimes appears under different designations, which complicates literature searches.
Most published studies on thymosin alpha-1 report changes in immune measurements rather than clinical outcomes, and findings differ across designs and populations. Whether the peptide signals through one defined receptor or through several less specific interactions remains an open question. Its reported circulation half-life of a few hours complicates comparison of dosing schedules across trials. Mechanistic claims are frequently drawn from isolated cell cultures, and how far those results extend to whole organisms is unresolved.
Thymosin alpha-1 is a synthetic peptide of 28 amino acids whose sequence matches the amino-terminal region of prothymosin alpha. The chain is acetylated at its first residue and contains one disulfide bridge between two cysteine residues, which folds the molecule into a compact loop. Its molecular formula, C129H215N33O55, corresponds to a monoisotopic mass of roughly 3,106 daltons. Material used in laboratories is made by solid-phase synthesis rather than isolated from animal tissue.
The 2012–13 season was Wenger's first without Rice, who retired in late spring. Bould was named as his replacement, who specialised in defensive work. Arsenal struggled to find consistency in the league and were 12 points behind leaders Manchester United by November 2012. A month later, Wenger came under strong criticism following his side's exit in the League Cup to Bradford City, when a full-strength team lost on penalties to opposition three divisions below. Further cup defeats to Blackburn Rovers and Bayern Munich in the FA Cup and Champions League, respectively, ended Arsenal's trophy chances for an eighth consecutive season. Before the first leg, Wenger had criticised the media for reporting he was about to sign a contract extension, and said of the Blackburn game: "We lost it in the last 20 minutes, so there are a lot of superficial analyses that you cannot accept. Because one guy says something, everybody goes the same way". Arsenal's aim of finishing in the top four appeared to be a difficult task by March, after defeat to Tottenham Hotspur. With ten league matches remaining, they were seven points behind their rivals, and Wenger said his side could not afford any more dropped points. He made changes to the side for their second leg against Bayern, dropping captain Thomas Vermaelen and Szczęsny, in place of Koscielny and Łukasz Fabiański. Though Arsenal were eliminated on the away goals rule, Wenger's adjustments worked in the league as his team went on a run to overhaul Tottenham for a second successive season.
Planned as an "adult release" (Japanese films were classified by the country's film board as "general release" or "adult"), the usual pace of production at Nikkatsu (10 days pre-production, 25 days shooting, three days post-production) allowed Suzuki and his innovative production designer Takeo Kimura precious little time to construct sets to recreate post-war firebombed Tokyo. Sets were slapped together on the backlot using materials purloined from studio warehouses, and theatrical set design techniques which could compromise the film's "realism." The resulting production has been lauded for its resulting visual flair. Most female actresses at Nikkatsu refused to work in the film due to the nudity and subject matter, so the cast's female roles were filled by actresses from outside the studio.
== Human nutrition == There is inconclusive clinical evidence on methionine supplementation. Dietary restriction of methionine can lead to bone-related disorders. Overconsumption of methionine, the methyl group donor in DNA methylation, is related to cancer growth in a number of studies.
== Safety, stability, regulations == Diethyl ether is extremely flammable and may form explosive vapour/air mixtures. Since ether is heavier than air it can collect low to the ground and the vapour may travel considerable distances to ignition sources. Ether will ignite if exposed to an open flame, though due to its high flammability, an open flame is not required for ignition. Other possible ignition sources include – but are not limited to – hot plates, steam pipes, heaters, and electrical arcs created by switches or outlets. Vapour may also be ignited by the static electricity which can build up when ether is being poured from one vessel into another. The autoignition temperature of diethyl ether is 160 °C (320 °F). The diffusion of diethyl ether in air is 9.18 × 10−6 m2/s (298 K, 101.325 kPa). Ether is sensitive to light and air, tending to form explosive peroxides. Ether peroxides have a higher boiling point than ether and are contact explosives when dry. Commercial diethyl ether is typically supplied with trace amounts of the antioxidant butylated hydroxytoluene (BHT), which reduces the formation of peroxides. Storage over sodium hydroxide precipitates the intermediate ether hydroperoxides. Water and peroxides can be removed by either distillation from sodium and benzophenone, or by passing through a column of activated alumina.
Sources: en.wikipedia.org
Since then, it has been applied worldwide to treat patients who are in need of new skin to treat massive burns and traumatic skin wounds, those undergoing plastic surgery of the skin, as well as others who have certain forms of skin cancer. In clinical practice, a thin graft sheet manufactured from the active collagen scaffold is placed on the injury site, which is then covered with a thin sheet of silicone elastomer that protects the wound site from bacterial infection and dehydration. The graft can be seeded with autologous cells (keratinocytes) in order to accelerate wound closure, however the presence of these cells is not required for regenerating the dermis. Grafting skin wounds with Integra leads to the synthesis of normal vascularized and innervated dermis de novo, followed by re-epithelization and formation of epidermis. Although early versions of the scaffold were not capable of regenerating hair follicles and sweat glands, later developments by S.T Boyce and coworkers led to solution of this problem. The mechanism of regeneration using an active collagen scaffold has been largely clarified. The scaffold retains regenerative activity provided that it has been prepared with appropriate levels of the specific surface (pore size in range 20-125 μm), degradation rate (degradation half-life 14 ± 7 days) and surface chemical features (ligand densities for integrins α1β1 and α2β1 must exceed approximately 200 μΜ α1β1 and α2β1 ligands).
=== Lungs === Fibrothorax Pulmonary fibrosis Cystic fibrosis Idiopathic pulmonary fibrosis (idiopathic meaning 'of unknown cause') Radiation-induced lung injury (following radiation therapies commonly used to treat cancer)
=== Recycling and transcytosis of IgG and serum albumin === FcRn extends the half-life of IgG and serum albumin by reducing lysosomal degradation of these proteins in endothelial cells and bone-marrow derived cells. The clearance rate of IgG and albumin is abnormally short in mice that lack functional FcRn. IgG, serum albumin and other serum proteins are continuously internalized into cells through pinocytosis. Generally, internalized serum proteins are transported from early endosomes to lysosomes, where they are degraded. Following entry into cells, the two most abundant serum proteins, IgG and serum albumin, are bound by FcRn at the slightly acidic pH (<6.5) within early (sorting) endosomes, sorted and recycled to the cell surface where they are released at the neutral pH (>7.0) of the extracellular environment. In this way, IgG and serum albumin are salvaged to avoid lysosomal degradation. This cellular mechanism provides an explanation for the prolonged in vivo half-lives of IgG and serum albumin and transport of these ligands across cellular barriers. In addition, for cell types bathed in an acidic environment such as the slightly acidic intestinal lumen, cell surface FcRn can bind to IgG, transport bound ligand across intestinal epithelial cells followed by release at the near neutral pH at the basolateral surface.
==== Symbolic AI and its limits ==== Symbolic AI (or "GOFAI") simulated the high-level conscious reasoning that people use when they solve puzzles, express legal reasoning and do mathematics. It was highly successful at some "intelligent" tasks such as algebra or IQ tests. In 1976, Newell and Simon proposed the physical symbol systems hypothesis: "A physical symbol system has the necessary and sufficient means of general intelligent action." However, the symbolic approach failed on many tasks that humans solve easily, such as learning, recognising an object or commonsense reasoning. Moravec's paradox is the discovery that high-level "intelligent" tasks were easy for AI, but low level "instinctive" tasks were extremely difficult. Philosopher Hubert Dreyfus had argued since the 1960s that human expertise depends on embodied, situational know-how that is not representable as explicit symbolic rules rather than conscious symbol manipulation, and on having a "feel" for the situation, rather than explicit symbolic knowledge. Although his arguments had been ridiculed and ignored when they were first presented, eventually, AI research came to agree with him. The issue is not resolved: sub-symbolic reasoning can make many of the same inscrutable mistakes that human intuition does, such as algorithmic bias.
=== REDEFINE 1 === In June 2025, results were published in the New England Journal of Medicine on REDEFINE 1, a 68-week, double-blind, Phase III clinical trial enrolling 3,417 participants, testing weekly cagrilintide 2.4 mg and semaglutide 2.4 mg individually and together versus placebo in obese/overweight subjects with comorbidities. People treated with CagriSema lost 20.4% of their body weight over 68 weeks, versus 11.5% with cagrilintide 2.4 mg alone, 14.9% with semaglutide 2.4 mg alone, and 3.0% with placebo.
Sources: en.wikipedia.org
=== Chemical reactions === Diallyl disulfide can be readily oxidized to allicin with hydrogen peroxide or peracetic acid. Allicin in turn can hydrolyze giving diallyl disulfide and trisulfide. Reaction of diallyl disulfide with liquid sulfur gives a mixture containing diallyl polysulfides with as many as 22 sulfur atoms in a continuous chain identified. When diallyl disulfide is heated it decomposes giving a complex mixture. The carbon-sulfur bond of diallyl disulfide is 16 kcal mol−1 weaker than the sulfur-sulfur bond (46 kcal mol−1 versus 62 kcal mol−1, respectively), with the consequence that on heating diallyl disulfide gives the allyldithio radical (AllSS•), which through addition to the double bonds in diallyl disulfide followed by fragmentation and subsequent reactions generates numerous organosulfur compounds, many of which are found in trace amounts in distilled garlic oil. In the presence of a catalyst, diallyl disulfide can combine with alkyl halides forming 1-alkylthio-3-allylthio-1-propene and 1,3-di(alkylthio)propene.
That same day, Peru and the OAS signed a joint declaration in favor of democracy and human rights. The OAS leader Luis Almagro said that "We have seen that president Castillo has much determination to fight corruption, especially corruption that may appear in his government. Let his management be as clean as possible. This requires important efforts in investigation. Let there be a permanent monitoring of transparency, of justice, so that there isn't any element of shadow over official members." On 5 December, Cuarto Poder finally released the audio clip. The audio showed the owner of the Breña house offering "scoops and headlines" to a journalist in exchange for the journalist shelving an unfavorable news story. The host of ATV news, Juliana Oxenford, claimed that it is "much more revealing to know the high content of trans fats in Cheese Tris than the audio of Cuarto Poder." Meanwhile, the journalist Juan Carlos Tafur said that the Cuarto Poder audio "qualifies as a journalistic scam." Following the release of the Cuarto Poder clips, the impeachment motion rapidly fell apart as less hardline members of the opposition rescinded their support for the impeachment motion. On 7 December 2021, with 46 in favor, 76 against, and 4 abstentions, Congress refused to admit the impeachment motion. Following the defeat of the impeachment motion, President Castillo said: "I am grateful that the congressional voted to put Peru first before other interests."
Acetyl-CoA carboxylase 1 (ACC1) Carbamoyl phosphate synthetase 1 (CPS1) Carnitine palmitoyltransferase 1 (CPT1) Enolase 1 (ENO1) Formyltetrahydrofolate dehydrogenase, 10- (ALDH1L1) Fructose bisphosphate aldolase B (ALDOB) Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) Histone H2B Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) Very long-chain acyl-CoA dehydrogenase (VLCAD)
Diurnal cycles of cortisol levels are found in humans. In humans, this cycle is characterized by high levels of cortisol early in the morning just before or at the time of waking. This is often known as the cortisol awakening response. Cortisol levels then decrease over the day with a nadir in the late evening. In addition to the diurnal rhythm over the day night cycle, cortisol is also released in an ultradian rhythm. This ultradian rhythm is characterized by hourly pulses of cortisol secretion.
The D'/D3 domain: Binds to factor VIII, heparin, and P-selectin. The A1 domain: Binds to the platelet GPIb-receptor, collagen types IV and VI, heparin, and osteoprotegerin. The A2 domain: Unfolds to expose the cleavage site for ADAMTS13 protease, which cleaves VWF into smaller multimers. Unfolding is influenced by blood shear flow, calcium binding, and a "vicinal disulfide" at the A2-domain's C-terminus. The A3 domain: Acts as the primary collagen binding site for VWF, binding to collagen types I and III. The C4 domain: Contains an RGD motif that binds to platelet integrin αIIbβ3. The CK (cystine knot) domain at the protein's C-terminal end: Involved in VWF dimerization. VWF is one of the few proteins carrying ABO blood group antigens. After glycosylation in the Golgi apparatus, VWF is packaged into storage granules, Weibel–Palade bodies (WPBs) in endothelial cells, and α-granules in platelets.
Sources: en.wikipedia.org
It is usually described as an immunomodulatory peptide rather than a classic circulating hormone. No endocrine gland is known to release it as a primary secretory product, and its measured presence in blood is not firmly established.
Prothymosin alpha is a much larger acidic protein, roughly 111 to 113 residues long, and the thymosin alpha-1 sequence matches its N-terminal region. The small peptide is therefore best understood as a fragment of that parent protein rather than a separate gene product.
Trials and clinical reports have examined chronic hepatitis B and C, use as a vaccine adjuvant, and supportive treatment in some immunodeficiency and oncology settings. Results vary by indication, and regulatory approval differs between countries.
它不是经典的内分泌激素，而是一种免疫调节肽。其作用主要通过局部免疫细胞间的信号传递实现，而非经血液循环作用于远隔器官。