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.
Updated 2026-04-28. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Identity and purity testing for thymosin alpha 1 relies mainly on reversed-phase high-performance liquid chromatography and mass spectrometry. Chromatography separates the parent peptide from truncated or modified variants, while mass spectrometry confirms the expected molecular mass. Amino acid analysis and peptide mapping provide additional sequence confirmation. Counterion content, water content, and residual solvents are measured separately as part of specification testing. No single method captures every attribute, so laboratories combine several techniques.
The peptide lacks cysteine, methionine, and tryptophan, so disulfide scrambling and sulfur oxidation are not major degradation routes. Instead, aspartate residues can undergo isomerization or cyclization to succinimide intermediates, generating isoaspartate variants. Hydrolysis of peptide bonds also occurs slowly in solution. These changes may reduce biological activity even when the main peak remains detectable. Stability studies therefore track both potency and the appearance of related substances.
Lyophilized thymosin alpha 1 is typically stored refrigerated at 2 to 8 degrees Celsius and kept away from light. Reconstituted solutions are less stable and are usually used promptly after preparation. Repeated freeze-thaw cycles are avoided because they can promote aggregation and loss of activity. The peptide adsorbs to some plastic and glass surfaces, so a carrier protein is often added to dilute working solutions. Manufacturer instructions and published protocols both govern handling.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Acetylated peptide | N-terminal acetyl group blocks aminopeptidase attack |
| Residue count | 28 amino acids | Matches the N-terminus of prothymosin alpha |
| Molecular mass | About 3,108 Da | Value for the free, unmodified peptide |
| Isoelectric point | Approximately 4.2 | Acidic; net negative charge at neutral pH |
| Encoding gene | PTMA | Human gene for the precursor protein |
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。
The name itself causes confusion, because several unrelated thymic peptides share the thymosin label. Thymosin beta-4, for example, is a different molecule with different functions. Naming conventions in the literature also mix descriptive research terms with assigned nonproprietary names, so a reader should confirm which entity a given paper addresses. Clarifying that point is usually the first step in interpreting any claim about this peptide.
Thymosin alpha-1 is a short peptide of 28 amino acid residues first described in the 1970s as a component of thymic extracts. Its N-terminal residue carries an acetyl group, and the sequence is highly conserved across mammalian species. The peptide is not encoded as a standalone gene product; it is released by proteolytic cleavage from the N-terminus of prothymosin alpha, a larger acidic nuclear protein. That precursor relationship places it within a broader family of thymic and immune-associated peptides that have been studied for decades.
The peptide was described in the 1970s as a component of thymic extracts, and early research focused on restoring immune function in immunodeficiency states. A synthetic version entered clinical development in the 1980s and is approved as a drug in several countries for conditions such as chronic hepatitis B and certain immunodeficiencies. Approval status varies widely by jurisdiction, and in the United States it is not an approved therapeutic. Regulatory and clinical positions differ, so statements about efficacy should be tied to specific indications and studies.
Thymosin alpha-1 is a synthetic peptide of 28 amino acids, corresponding to the N-terminal fragment of prothymosin alpha. Its sequence begins with acetylation at the N-terminus, a modification that affects stability and receptor interaction. The peptide is acidic, with a calculated isoelectric point near 4.2, and carries no disulfide bonds, so its secondary structure is largely flexible in solution. Molecular mass is approximately 3108 daltons. The native form was first isolated from bovine thymus tissue, while pharmaceutical material is produced by solid-phase peptide synthesis.
Within the immune system, the peptide acts on several cell types rather than a single target. Reported activities include promotion of T-cell maturation, enhancement of natural killer cell activity, and modulation of cytokine production by dendritic cells and macrophages. Some of these effects appear to operate through toll-like receptor signaling, though the precise receptor-level mechanism remains debated. Whether the observed immune changes translate into clinical benefit is a separate question and depends on the indication studied.
The ISOLDE facility contains the Class A laboratories, buildings for the HIE-ISOLDE and MEDICIS projects, and the control rooms located in building 508. Before ISOLDE, the radioactive nuclides were transported from the production are to the laboratory for examination. At ISOLDE, all processes from the production to the measurements are connected and the radioactive material requires no extra transport. Due to this, ISOLDE is referred to as an on-line facility. At the ISOLDE facility, the main proton beam for reactions comes from the PSB. The incoming proton beam has an energy of 1.4 GeV and its average intensity varies up to 2 μA. The beam enters the facility and is directed towards one of two mass separators: the General Purpose Separator (GPS) and the High Resolution Separator (HRS). The separators have independently run target-ion source systems, delivering 60 keV RIBs.
Artificially acquired active immunity can be induced by a vaccine, a substance that contains antigen. A vaccine stimulates a primary response against the antigen without causing symptoms of the disease. The term vaccination was coined by Richard Dunning, a colleague of Edward Jenner, and adapted by Louis Pasteur for his pioneering work in vaccination. The method Pasteur used entailed treating the infectious agents for those diseases, so they lost the ability to cause serious disease. Pasteur adopted the name vaccine as a generic term in honor of Jenner's discovery, which Pasteur's work built upon. In 1807, Bavaria became the first group to require their military recruits to be vaccinated against smallpox, as the spread of smallpox was linked to combat. Subsequently, the practice of vaccination would increase with the spread of war. There are four types of traditional vaccines:
The light chain gene has three gene segments. These include: the light chain variable region (V), joining region (J), and constant region (C) gene segments. The variable region of light is therefore encoded by the rearrangement of VJ segments. The light chain can be either kappa,κ or lambda,λ. This process takes place at the level of mRNAs processing. Random rearrangements and recombinations of the gene segments at DNA level to form one kappa or lambda light chain occurs in an orderly fashion. As a result, "a functional variable region gene of a light chain contains two coding segments that are separated by a non-coding DNA sequence in unrearranged germ-line DNA".
=== Energy released === The average energy released per fission of uranium-233 is about 197.9 MeV = 3.171·10−11 J (i.e. 19.09 TJ/mol = 81.95 TJ/kg = 22764 MWh/kg that is 1.8 million times more than the same mass of diesel).
Sources: en.wikipedia.org
Ecnoglutide (XW003) is a GLP-1 agonist being developed for the treatment of obesity and type 2 diabetes. In preclinical trials, "Ecnoglutide showed a favorable potency, pharmacokinetic, and tolerability profile, as well as a simplified manufacturing process" compared to other GLP-1 agonist lipopeptides. A phase 3 trial published in 2025 showed 9-13% reduction in bodyweight versus placebo over a 48-week treatment, varying by ecnoglutide dose. In January 2026, ecnoglutide injection is approved for marketing in China.
The alkanes from pentane (C5H12) to octane (C8H18) are refined into gasoline, the ones from nonane (C9H20) to hexadecane (C16H34) into diesel fuel, kerosene and jet fuel. Alkanes with more than 16 carbon atoms can be refined into fuel oil and lubricating oil. At the heavier end of the range, paraffin wax is an alkane with approximately 25 carbon atoms, while asphalt has 35 and up, although these are usually cracked in modern refineries into more valuable products. The lightest fraction, the so-called petroleum gases, are subjected to diverse processing depending on cost. These gases are either flared off, sold as liquefied petroleum gas, or used to power the refinery's own burners. During the winter, butane (C4H10) is blended into the gasoline pool at high rates because its high vapour pressure assists with cold starts. The aromatic hydrocarbons are unsaturated hydrocarbons that have one or more benzene rings. They tend to burn with a sooty flame, and many have a sweet aroma. Some are carcinogenic. These different components are separated by fractional distillation at an oil refinery to produce gasoline, jet fuel, kerosene, and other hydrocarbon fractions. The components in an oil sample can be determined by gas chromatography and mass spectrometry. Due to the large number of co-eluted hydrocarbons within oil, many cannot be resolved by traditional gas chromatography. This unresolved complex mixture (UCM) of hydrocarbons is particularly apparent when analysing weathered oils and extracts from tissues of organisms exposed to oil.
=== Pusha T's solo career and work relationship with GOOD Music === Before releasing any solo material, Pusha T signed in the autumn of 2010 to GOOD Music, a record label founded by West. That year, he appeared on multiple songs in West's GOOD Fridays series, rapped in the GOOD cypher at the BET Hip Hop Awards, and had two features on West's album My Beautiful Dark Twisted Fantasy. The creative partnership was fruitful; Pusha T became president of GOOD in 2015, and West had production credits on all of his commercially released albums until It's Almost Dry. Pusha T was publicly outspoken about not seeing eye-to-eye with West on politics and career moves multiple times. Among other examples, he expressed disagreement over West's support of Donald Trump and claimed to have different principles on music industry relationships. The relationship had completely deteriorated by late 2022, after West made statements widely condemned as antisemitic. Pusha T said the following in response to West's comments: "It's definitely affected me. It's been disappointing. As a Black man in America, there is no room for bigotry or hate speech. So yeah. It's been very disappointing, let's talk straight." In another interview, he said: "It's beyond [wild stuff] and it's nothing to tap dance around. It's wrong. Period." and "He's not speaking to me now. If you ain't with it, you ain't down. And I ain't with it. I'm not budging on that. I'm not with it." He also clarified that he was no longer the president of GOOD or affiliated with the label in any way.
=== Radioactive contamination === RTGs pose a risk of radioactive contamination: if the container holding the fuel leaks, the radioactive material may contaminate the environment. For spacecraft, the main concern is that if an accident were to occur during launch or a subsequent passage of a spacecraft close to Earth, harmful material could be released into the atmosphere; therefore their use in spacecraft and elsewhere has attracted controversy. However, this event is not considered likely with current RTG cask designs. For instance, the environmental impact study for the Cassini–Huygens probe launched in 1997 estimated the probability of contamination accidents at various stages in the mission. The probability of an accident occurring which caused radioactive release from one or more of its three RTGs (or from its 129 radioisotope heater units) during the first 3.5 minutes following launch was estimated at 1 in 1,400; the chances of a release later in the ascent into orbit were 1 in 476; after that the likelihood of an accidental release fell off sharply to less than 1 in a million. If an accident which had the potential to cause contamination occurred during the launch phases (such as the spacecraft failing to reach orbit), the probability of contamination actually being caused by the RTGs was estimated at 1 in 10. The launch was successful and Cassini–Huygens reached Saturn. To minimize the risk of the radioactive material being released, the fuel is stored in individual modular units with their own heat shielding.
Ag+O2− + H2C=CH2 → (CH2CH2)O + AgO The resulting silver oxide then oxidizes ethylene or ethylene oxide to CO2 and water. This reaction replenishes the silver catalyst. Thus the overall reaction is expressed as
Sources: en.wikipedia.org
Thymosin fraction 5 is a mixture of many peptides obtained from thymus tissue, while thymosin alpha 1 is a single defined 28-residue molecule. The two names appear together in older literature because the purified peptide was first obtained from that mixture.
The precursor, prothymosin alpha, is encoded by the PTMA gene in humans. The 28-residue peptide corresponds to the N-terminal segment released from that larger protein.
It is produced as a fragment of prothymosin alpha and is present in many tissues. Circulating concentrations are low, which makes routine measurement difficult.
The lyophilized powder is kept refrigerated at 2 to 8 degrees Celsius and protected from light. Reconstituted solutions should be used promptly. Freezing and thawing repeatedly is avoided.