If you have been reading about thymalfasin and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-08-25. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Practical handling focuses on limiting adsorption and contamination. The peptide dissolves readily in water, and dilute solutions tend to adhere to plastic and glass surfaces, so an inert carrier protein or a defined buffer can reduce losses in laboratory work. Workers also record the counter-ion form, since an acetate or trifluoroacetate salt changes the mass balance of the weighed powder. Documentation of lot number, purity value, and storage history supports reproducibility when results from different laboratories are compared.
Lyophilized material is generally held at reduced temperature to slow degradation, and storage at minus twenty degrees Celsius or lower is common practice for long-term retention. Short-term working portions are often kept between two and eight degrees Celsius. Once dissolved, the peptide is less stable than the dry powder, and repeated freeze-thaw cycles are associated with loss of material and with aggregate formation. Vials are usually allowed to reach room temperature before opening so that condensation does not introduce moisture, and solutions are protected from light where practical.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography, which separates the peptide from closely related impurities and from truncated or oxidized variants. Mass spectrometry supplies the molecular mass and confirms the expected sequence length, while amino acid analysis can be used to check composition. Because the molecule has no chromophore beyond the peptide backbone, ultraviolet detection is typically performed at a low wavelength, where baseline interference from solvents and buffers is a practical concern. Water content and counter-ion content are often reported alongside purity.
| 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 |
Biologically, the peptide is studied mainly in the context of immune cell development and regulation. It is produced in the thymus and in several other tissues, and it appears to influence the maturation and activity of T cells and other immune populations. Laboratory work describes effects on cytokine production, on the balance between T cell subsets, and on the function of dendritic cells. Much of this evidence comes from cell culture and animal models, so the extent to which the same pathways operate in humans remains an open question.
Clinical interest has centered on chronic viral hepatitis, on immune restoration in various conditions, and on use as an adjuvant intended to improve responses to vaccines. Trials have reported mixed results, and regulatory status differs sharply between countries; in some places it is a prescription product, while elsewhere it is sold without an approved therapeutic indication. Because published studies vary widely in design, population, and endpoints, comparisons across them are difficult and no single conclusion covers the whole literature.
Thymosin alpha 1 is a short peptide of 28 amino acid residues that derives from the amino terminal region of a larger precursor protein known as prothymosin alpha. The peptide carries an acetyl group on its first residue and contains no disulfide bonds or carbohydrate chains. Its sequence is highly conserved across mammalian species, which is one reason laboratories treat it as a molecule with a defined and reproducible structure rather than a variable tissue extract. The name follows an early naming convention for thymus-derived fractions and does not imply that the peptide acts as a hormone in the classical endocrine sense.
临床研究将Tα1用于慢性病毒感染、肿瘤辅助治疗和疫苗佐剂等场景。部分试验报告了免疫学指标改善，但临床终点获益在不同研究中并不一致。系统综述指出，研究间在人群、剂量和联合方案上差异较大，难以汇总结论。因此，Tα1的确切临床地位仍属开放问题，需要更多高质量随机对照试验来澄清。其机制研究也需从体外实验向体内模型推进。
胸腺素α1对免疫系统的影响涉及多种细胞类型。研究表明，它可促进未成熟T细胞向成熟T细胞分化，并增强T细胞对抗原刺激的增殖反应。树突状细胞在Tα1存在下表达更高水平的共刺激分子，从而更有效地呈递抗原。此外，自然杀伤细胞的活性也观察到上升。这些效应并非直接杀伤病原体，而是调节宿主免疫应答的强度与方向。
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。
Bradykinin is rapidly inactivated in the circulating blood, and it disappears completely in a single pass through the pulmonary circulation. Angiotensin I also disappears in the pulmonary circulation because of its conversion to angiotensin II. Furthermore, angiotensin II passes through the lungs without any loss. The inactivation of bradykinin and the conversion of angiotensin I to angiotensin II in the lungs was thought to be caused by the same enzyme. In 1970, Ng and Vane, using BPF provided by Ferreira, showed the conversion is inhibited during its passage through the pulmonary circulation. BPFs are members of a family of peptides whose potentiating action is linked to inhibition of bradykinin by ACE. Molecular analysis of BPF yielded a nonapeptide BPF teprotide (SQ 20,881), which showed the greatest ACE inhibition potency and hypotensive effect in vivo. Teprotide had limited clinical value as a result of its peptide nature and lack of activity when given orally. In the early 1970s, knowledge of the structure-activity relationship required for inhibition of ACE was growing. David Cushman, Miguel Ondetti and colleagues used peptide analogs to study the structure of ACE, using carboxypeptidase A as a model. Their discoveries led to the development of captopril, the first orally-active ACE inhibitor, in 1975. Captopril was approved by the United States Food and Drug Administration in 1981. The first nonsulfhydryl-containing ACE inhibitor, enalapril, was approved four years later. At least 8 other ACE inhibitors have since been marketed.
A memorandum to end the war was signed on 17 June by the presidents of the US and Iran, lifting the dual blockade. Tensions again escalated, but on 28 June, the US and Iran agreed to cease their exchange of attacks. On 8 July, the ceasefire deal between the US and Iran collapsed after Iran initiated attacks on commercial vessels in the Strait of Hormuz to assert sovereignty over the strait, which interrupted a brief diplomatic lull.
On 15 October, when President Abdirashid Ali Sharmarke was touring Las Anood, his bodyguard killed him, he was acting on his own accord, according to Henry Kissinger. Six days later, on 21 October, General Siad Barre led a military coup which overthrew the parliamentary government. The coup was motivated by corruption. The bodyguard was tried and executed by the Supreme Revolutionary Council (SRC). He came from the same clan background as the president. Alongside Barre, the SRC was led by Brigadier General Mohamed Ainanshe Guled, Lieutenant Colonel Salaad Gabeyre Kediye, and Chief of Police Jama Korshel. Kediye officially held the title "Father of the Revolution", and afterwards, Barre became the head of the SRC. The SRC subsequently renamed the country to the Somali Democratic Republic, dissolved the parliament and the Supreme Court, and suspended the constitution.
Rachel Frances Shaw (born 1981 or 1982) is an American actress, writer and director. She is best known for playing Bridgette Bird on the Showtime series SMILF, based on the 2015 short film of the same title, which she wrote, directed and starred in. Shaw is also known for playing Mary Jo Cacciatore on the 2010–2011 Spike TV series Blue Mountain State, and her recurring role as Shayla Nico in the first season of the USA Network television series Mr. Robot.
==== 109th Congress ==== On October 27, 2005, Hastert became the first Speaker to author a blog. On "Speaker's Journal" on his official U.S. House website, Hastert wrote in his first post: "This is Denny Hastert and welcome to my blog. This is new to me. I can't say I'm much of a techie. I guess you could say my office is teaching the old guy new tricks. But I'm excited. This is the future. And it is a new way for us to get our message out." On June 1, 2006, Hastert became the longest-serving Republican Speaker of the House in history, surpassing the record previously held by fellow Illinoisan Joseph Gurney Cannon, who held the post from November 1903 to March 1911. In 2005, following Hurricane Katrina, Hastert told an Illinois newspaper that "It looks like a lot of that place [referring to New Orleans] could be bulldozed" and stated that spending billions of dollars to rebuild the devastated city "doesn't make sense to me." The remarks enraged Governor Kathleen Blanco of Louisiana, who stated that Hastert's comments were "absolutely unthinkable for a leader in his position" and demanded an immediate apology.
Sources: en.wikipedia.org
Intussusceptive angiogenesis, also known as splitting angiogenesis, is the formation of a new blood vessel by splitting an existing blood vessel into two. Intussusception was first observed in neonatal rats. In this type of vessel formation, the capillary wall extends into the lumen to split a single vessel in two. There are four phases of intussusceptive angiogenesis. First, the two opposing capillary walls establish a zone of contact. Second, the endothelial cell junctions are reorganized and the vessel bilayer is perforated to allow growth factors and cells to penetrate into the lumen. Third, a core is formed between the 2 new vessels at the zone of contact that is filled with pericytes and myofibroblasts. These cells begin laying collagen fibers into the core to provide an extracellular matrix for growth of the vessel lumen. Finally, the core is fleshed out with no alterations to the basic structure. Intussusception is important because it is a reorganization of existing cells. It allows a vast increase in the number of capillaries without a corresponding increase in the number of endothelial cells. This is especially important in embryonic development as there are not enough resources to create a rich microvasculature with new cells every time a new vessel develops.
α-ketoglutarate + AcCoA → homocitrate → L-α-aminoadipic acid → L-lysine + β-lactam The Penicillium cells are grown using a technique called fed-batch culture, in which the cells are constantly subjected to stress, which is required for induction of penicillin production. While the usage of glucose as a carbon source represses penicillin biosynthesis enzymes, lactose does not exert any effect and alkaline pH levels override this regulation. Excess phosphate, available oxygen, and usage of ammonium as a nitrogen source repress penicillin production, while methionine can act as a sole nitrogen/sulfur source with stimulating effects. The biotechnological method of directed evolution has been applied to produce by mutation a large number of Penicillium strains. These techniques include error-prone PCR, DNA shuffling, ITCHY and strand-overlap PCR.
==== Elimination ==== The mean elimination half-life of carvedilol following oral administration ranges from 7 to 10 hours. The pharmaceutical product is a mix of two enantiomorphs, R(+)-carvedilol and S(–)-carvedilol, with differing metabolic properties. R(+)-Carvedilol undergoes preferential selection for metabolism, which results in a fractional half-life of about 5 to 9 hours, compared with 7 to 11 hours for the S(-)-carvedilol fraction.
=== Molecular machinery === Molecular machines are molecules or molecular assemblies that can perform functions such as linear or rotational movement, switching, and entrapment. These devices exist at the boundary between supramolecular chemistry and nanotechnology, and prototypes have been demonstrated using supramolecular concepts. Jean-Pierre Sauvage, Sir J. Fraser Stoddart and Bernard L. Feringa shared the 2016 Nobel Prize in Chemistry for the 'design and synthesis of molecular machines'.
Sources: en.wikipedia.org
** not really an RTG, the BES-5 Buk (БЭС-5) reactor was a fast reactor which used thermocouples based on semiconductors to convert heat directly into electricity *** not really an RTG, the SNAP-10A used enriched uranium fuel, zirconium hydride as a moderator, liquid sodium potassium alloy coolant, and was activated or deactivated with beryllium reflectors Reactor heat fed a thermoelectric conversion system for electrical production. **** not really an RTG, the ASRG uses a Stirling power device that runs on radioisotope (see Stirling radioisotope generator)
In June 2021, Biden took his first trip abroad as president, visiting Belgium, Switzerland, and the United Kingdom. He attended a G7 summit, a NATO summit, and an EU summit, and held one-on-one talks with Russian president Vladimir Putin. In September 2021, Biden announced AUKUS, a defense pact between Australia, the United Kingdom and the United States, to ensure "peace and stability in the Indo-Pacific". In February 2021, the Biden administration announced that the United States was ending its support for the Saudi-led bombing campaign in Yemen and revoked the designation of Yemen's Houthis as terrorists. In early February 2022, Biden ordered the counterterrorism raid in northern Syria that resulted in the death of Abu Ibrahim al-Hashimi al-Qurashi, the second leader of the Islamic State. In late July, Biden approved the drone strike that killed Ayman al-Zawahiri, the second leader of Al-Qaeda, and an integral member in the planning of the September 11 attacks. The 2022 OPEC+ oil production cut caused a diplomatic spat with Saudi Arabia, threatening a longstanding alliance. In August 2024, Biden negotiated and oversaw the 2024 Ankara prisoner exchange, the largest prisoner exchange since the end of the Cold War. It involved the release of 26 people, including journalist Evan Gershkovich and former Marine Paul Whelan. In November 2024, the Biden administration announced that it had helped broker a ceasefire agreement in the Israel–Hezbollah conflict.
==== Others ==== Blonanserin – Approved by the PMDA in 2008. Used in Japan and South Korea. Pimavanserin – A selective 5-HT2A receptor antagonist approved for the treatment of Parkinson's disease psychosis in 2016. Sertindole ‡ – Developed by the Danish pharmaceutical company H. Lundbeck. Like the other atypical antipsychotics, it is believed to have antagonist activity at dopamine and serotonin receptors in the brain.
== Synthesis == Calcination of lanthanum(III) sulfate in oxygen current at 750 °C: La2(SO4)3 + O2 → La2O3·SO3 + 2SO3 The resulting product is reduced with hydrogen when heated: La2O3·SO3 + 4H2 → La2O2S + 4H2O
==== Other ==== Treatment of breast cancer in women, although they are now rarely used for this purpose due to their marked virilizing side effects. In low doses as a component of hormone therapy for postmenopausal and transgender women, for instance to increase energy, well-being, libido, and quality of life, as well as to reduce hot flashes. Testosterone is usually used for this purpose, although methyltestosterone is also used. Male hormonal contraception; currently experimental, but potential for use as effective, safe, reliable, and reversible male contraceptives. Assistant in the treatment of Raynaud's Phenomenon and peripheral acrocyanosis. Testosterone and other anabolics tend to be potent vasodilators, which can significantly improve bloodflow in individuals prone to vasoconstriction.
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.
Cool storage below freezing is usual for long-term retention, with a desiccant and protection from light. Portions are often split before first use to avoid repeated handling.