Everything below concerns thymosin alpha 1. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-08-20. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular mass | Approximately 3,108 Da | Consistent with a 28-residue acetylated peptide |
| Residue count | 28 | Corresponds to the amino terminal region of prothymosin alpha |
| Appearance of dry powder | White to off-white solid | Slight variation between lots is normal |
| Solubility class | Freely soluble in water | Low solubility in most organic solvents |
| Common synonyms | Thymosin alpha 1, T alpha 1 | The numeral reflects an early fraction numbering scheme |
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。
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。
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.
Atherosclerosis – a hardening of the arteries Sickle cell disease – an inherited blood disorder that can block circulation throughout the body, primarily affecting people of sub-Saharan origin. Myasthenia gravis Systemic sclerosis Sinusitis Sjogren's Syndrome - an autoimmune disease that primarily attacks the lacrimal and salivary glands, but also impacts other organs such as the lungs, kidneys, liver, and nervous system.
=== Inheritance === This condition is inherited in a mitochondrial pattern, which is also known as maternal inheritance and heteroplasmy. This pattern of inheritance applies to genes contained in mitochondrial DNA. Because egg cells, but not sperm cells, contribute mitochondria to the developing embryo, only females pass mitochondrial conditions to their children. Mitochondrial disorders can appear in every generation of a family and can affect both males and females, but fathers do not pass mitochondrial traits to their children. In most cases, people with MELAS inherit an altered mitochondrial gene from their mother. Less commonly, the disorder results from a new mutation in a mitochondrial gene and occurs in people with no family history of MELAS. Although first recognised and described in 1984 the condition occurred well before that date. Josiah Wedgwood gave detailed description of this illness in his youngest daughter, Mary Ann Wedgwood (1778–1786). Her illness may provide a link to the illnesses that afflicted her elder brother, Thomas Wedgwood, her eldest sister Susannah Darwin, and Susannah's second son, the famous naturalist, Charles Darwin. The illnesses that afflicted the Wedgwood-Darwin families have a well defined matrilineal inheritance pattern.
Strychnine was commonly used as an athletic performance enhancer and stimulant in the late 19th century and early 20th century. The best-known incident of this usage was during the 1904 Olympics marathon, when track-and-field athlete Thomas Hicks was administered a concoction of egg whites and brandy that contained strychnine by his assistants in an attempt to boost his stamina; Hicks did not know that it contained strychnine. Maximilian Theodor Buch proposed that strychnine was a cure for alcoholism. Although strychnine has no known addictive properties, in The Invisible Man (1897), H. G. Wells imagined the protagonist, Griffin, to be a strychnine addict:
Sources: en.wikipedia.org
In legal contexts, in situ is often used for its literal sense, meaning 'in its original place'. In Hong Kong, in-situ land exchange refers to a mechanism whereby landowners can swap their existing or expired land leases for new grants covering the same land parcel. This approach facilitates redevelopment—such as modernizing buildings or increasing land usage density—in a crowded, land-scarce environment without displacing ownership from the original location. The Hong Kong government, through the Development Bureau and Lands Department, has implemented arrangements to expedite lease modifications and land exchanges. In public international law, the term in situ is used to distinguish between a government that exercises effective control over a state's territory and population and a government-in-exile, which operates from outside its national borders. A government in situ is the de facto governing authority, while a government-in-exile may still claim legitimacy despite lacking territorial control. The recognition of a government generally depends on its ability to maintain authority over its state, though exceptions exist, particularly when a government-in-exile is displaced due to unlawful foreign occupation.
== Applications == Desalting is used to remove salts from protein solutions, phenol or unincorporated nucleotides from nucleic acids or excess crosslinking or labeling reagents from conjugated proteins. Buffer exchange is used to transfer a protein solution into a buffer system appropriate for downstream applications such as ion exchange, electrophoresis or affinity chromatography.
Albany is in the central part of Oregon's most populated region, the Willamette Valley. The city rests along the confluence of the Calapooia and Willamette rivers, and although most of Albany falls within Linn County, a smaller portion of the city rests to the north of its downtown on the west bank of the Willamette River in Benton County. According to the United States Census Bureau, the city has a total area of 17.75 square miles (45.97 km2), of which 17.54 square miles (45.43 km2) is land and 0.21 square miles (0.54 km2) is water. Albany has 21.7 square miles (56 km2) within its urban growth boundary. Throughout the city limits and urban growth area, there are limited hills; the city is one of the lowest points along the Willamette Valley, with elevations ranging 180 to 430 feet (55 to 131 m) above sea level. The North Albany district has the most variable elevation, while the downtown and southern end of town have little elevation change throughout.
Sources: en.wikipedia.org
The name reflects an early convention for naming thymus-derived fractions. The peptide is characterized and measured as a defined molecule, and it does not operate through a single classical endocrine axis.
It is a 28-residue synthetic peptide studied as an immune-modulating agent and approved as a drug in some countries. The sequence matches a naturally occurring fragment isolated from thymus tissue. It is not a hormone in the endocrine sense.
The name traces back to thymosin fraction 5, a crude thymus extract examined in the 1970s. Individual peptides in that mixture were labeled with Greek letters, and alpha-1 was one of them. The international nonproprietary name thymalfasin was assigned later.
No. Thymosin beta-4 contains 43 residues and binds actin, while thymosin alpha-1 contains 28 residues and acts on immune cells. The two sit in a historical naming group but share no sequence similarity, and they are not substitutes for one another.