胸腺素α1 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 2026-07-20. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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。
胸腺素α1（thymosin alpha 1，Tα1）是一种由28个氨基酸组成的酸性肽，N端被乙酰化，分子量约为3108道尔顿。该肽最早从牛胸腺组织提取物中分离，属于胸腺素组分5的一个成分。其序列在不同哺乳动物中高度保守，提示其具有基本的生物学功能。名称中的“α1”指其在电泳中的迁移位置，并非表示亚型编号。它既存在于胸腺，也存在于脾脏和淋巴结等免疫组织。
| Property | Value | Notes |
|---|---|---|
| Class | Synthetic peptide | 28 residues; not a small-molecule compound |
| Molecular mass | About 3,106 Da | Monoisotopic mass of the unmodified chain |
| N-terminal group | Acetylated serine | Present in both native and synthetic forms |
| Secondary structure | Disulfide-constrained loop | One bridge between two cysteine residues |
| Typical source | Solid-phase synthesis | Early isolates came from bovine thymus extracts |
Thymosin beta-4 is a separate 43-residue peptide that binds actin and participates in cell migration; it shares no sequence similarity with thymosin alpha-1 despite the common family name. Other preparative materials, such as thymosin fraction 5 and thymopoietin, contain distinct mixtures or peptides. The shared thymosin label reflects the tissue of origin used in early purification, not a common structural core. Treating these molecules as interchangeable is a frequent source of confusion in laboratory reports and in popular summaries alike.
Thymosin alpha-1 is a synthetic peptide of 28 amino acid residues that corresponds to a naturally occurring fragment first isolated from thymus tissue. Its chain is acetylated at the amino terminus, a modification that shields the peptide from rapid cleavage by aminopeptidases. The molecule carries a net negative charge at physiological pH and dissolves freely in water. Researchers classify it as an immune-modulating agent rather than a classical hormone, because it acts on several cell types of both the innate and the adaptive immune system.
The peptide was identified during work in the 1970s on thymosin fraction 5, a partially purified extract of calf thymus. Investigators separated that mixture and characterized individual components, one of which they named thymosin alpha-1. The same compound later received the international nonproprietary name thymalfasin. Commercial material is produced by solid-phase peptide synthesis rather than by extraction, so synthetic and natural forms share an identical sequence. Naming conventions vary across the literature, and readers should distinguish the alpha-1 peptide from other thymosins that have unrelated sequences and functions.
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.
In July 2021, all family size limits as well as penalties for exceeding them were removed. Since abandoning population control restrictions, China has pursued pro-natalist policies in an attempt to boost the birth rate.
On 20 August 2020, Russian opposition leader Alexei Navalny fell ill during a flight from Tomsk to Moscow. The plane made an emergency landing in Omsk, where Navalny was hospitalized and put in a medically induced coma. His family suspected his illness was caused by a poison put into a cup of tea he drank before the flight. He was evacuated to the Charité hospital in Berlin, Germany, the following day. On 2 September, the German government said that it had "unequivocal evidence" that Navalny was poisoned by a Novichok agent after tests at a German military lab and had called on the Russian government for an explanation, with labs in France and Sweden corroborating the findings. On 4 September, the North Atlantic Council was briefed by the German representative on the "appalling assassination attempt on" Navalny. In a post-meeting press conference, Secretary-General Jens Stoltenberg said that NATO allies "agree that Russia has serious questions it must answer", that the OPCW needed to conduct an impartial investigation, that "those responsible for this attack must be brought to justice" and called on Russia to "provide complete disclosure of the Novichok programme to the OPCW." Navalny had been out of his coma since 7 September. On 6 October, the OPCW confirmed the presence of a cholinesterase inhibitor from the Novichok group in Navalny's blood and urine samples. At the same time, the OPCW report clarified that Navalny was poisoned with a new type of Novichok, which was not included in the list of controlled chemicals of the Chemical Weapons Convention.
RaTG13 was sampled from bats in a mine in Mojiang County, Yunnan, located roughly 1,500 km (930 mi) away from Wuhan, and there are relatively few bat coronaviruses from Hubei province, where Wuhan is located.
Instant coffee (Two packets) Coffee creamer (One packet, four grams) Sugar (One packet, six grams) Candy-coated gum (Two pieces) Compressed fruitcake bar or Tropical Bar Toilet paper Cardboard matches (One book) Cigarettes (Four sticks; eliminated in 1975) Although compact, the LRP daily ration was 'energy depleted', supplying 5,000 kilojoules (1,200 kcal) less energy per day than the MCI.
Sources: en.wikipedia.org
The study determined that eudaimonically oriented participants reported their parents had been both demanding and responsive towards them. A multiple regression showed that demandingness and responsiveness together explained as much as twenty-eight percent of the variance in eudaimonia, this suggests parenting played a major role in the development of this pursuit. This supported the expectation that eudaimonia is cultivated when parents encourage internal structure, self-discipline, responsibility, and vision, and simultaneously fulfill a child's needs for autonomy. The research concludes that parents who want their children to experience eudaimonia must firstly themselves "mentor" their children in the approaches to attain eudaimonia. To encourage eudaimonia verbally is not sufficient to suffice eudaimonia into adulthood. Parents must clearly role model eudaimonia for it to truly be present in the child's life.
The most notable and recognisable series of advertisements was created by S. H. Benson's advertising, primarily drawn by the artist John Gilroy, in the 1930s and 1940s. Benson created posters that included phrases such as "Guinness for Strength", "Lovely Day for a Guinness", "Guinness Makes You Strong", "My Goodness My Guinness" (or, alternatively, "My Goodness, My Christmas, It's Guinness!"), and most famously, "Guinness Is Good for You". While modern alcohol advertising regulations prohibit such claims, vintage artefacts with the slogans remain common in Irish pubs.
=== September === September 1 Following reports of tensions with US Defense Secretary Pete Hegseth, US Army Secretary Daniel P. Driscoll steps down. The U.S. announces that it struck IRGC targets in Iran after the latter's attacks on commercial shipping in Hormuz and its soldiers, adding that it targeted tankers owned by the National Iranian Oil Company as part of its new "tanker to tanker" policy. Trump states that a most devastating attack is in the works, adding that when it is complete the Iranian government will be in ruins. Trump announces that a major target of those strikes were Iran's efforts to rebuild its radar system. Over $560,000 in cryptocurrency donations for Hamas are seized by the Justice Department. LGBTQ rights in the United States: The Department of Justice files a lawsuit against the Kansas City Public Schools district over its policies that allow transgender students to share their preferred name, gender, and pronouns with school staff. September 2 Birthright citizenship in the United States: American federal judge Deborah Boardman of the U.S. District Court for the District of Maryland blocks an attempt by the Trump administration to implement an executive order aimed at ending birthright citizenship in the United States. Hegseth extends the deployments of approximately 50,000 American soldiers in West Asia, which include warship crews, air defense units, and paratroopers, until 2027. September 3 Chipmaker Nvidia agrees to buy the Hugging Face AI platform in a deal worth $12.9 billion.
ADPRase is a dimer of two identical monomers, each of which contain 209 amino acids. The two monomers are folded into two distinct structural domains and with two equivalent catalytic sites. The C-terminal domain consists of the Nudix sequence mentioned above and the N-terminal domain is primarily involved in dimer stabilization. As noted earlier, the Nudix fold is the catalytic part of the enzyme, but both domains are involved in the active site and they both help with the attachment and coordination of H2O, Mg2+, and the ADP-ribose substrate.
Double-stranded RNA (dsRNA) is RNA with two complementary strands, similar to the DNA found in all cells, but with the replacement of thymine by uracil and the adding of one oxygen atom. dsRNA forms the genetic material of some viruses (double-stranded RNA viruses). Double-stranded RNA, such as viral RNA or siRNA, can trigger RNA interference in eukaryotes, as well as interferon response in vertebrates. In eukaryotes, double-stranded RNA (dsRNA) plays a role in the activation of the innate immune system against viral infections. In the late 1970s, it was shown that there is a single stranded covalently closed, i.e. circular form of RNA expressed throughout the animal and plant kingdom (see circRNA). circRNAs are thought to arise via a "back-splice" reaction where the spliceosome joins a upstream 3' acceptor to a downstream 5' donor splice site. So far the function of circRNAs is largely unknown, although for few examples a microRNA sponging activity has been demonstrated.
Sources: en.wikipedia.org
Its sequence corresponds to the amino-terminal portion of prothymosin alpha, a larger protein present in many cell types. The isolated 28-residue peptide is a fragment of that protein rather than a separately encoded molecule, and laboratory material is produced by synthesis.
The single bridge between two cysteine residues holds the chain in a folded loop that influences its shape and its behavior in solution. Loss of the bridge through reduction or oxidation shifts chromatographic retention and is tracked during stability work.
It is a defined 28-residue sequence derived from a larger precursor, whereas many other thymic preparations are mixtures of several polypeptides. Its acetylated amino terminus and single disulfide bridge distinguish it chemically from unrelated thymic extracts.
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。