This is a working overview of thymosin alpha 1, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-02-15. Anything still debated is marked as such rather than presented as settled.
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.
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.
Like most short peptides, thymosin alpha-1 is susceptible to hydrolysis under strongly acidic or basic conditions and to oxidation when exposed to air over long periods. The acetylated amino terminus blocks one common degradation route, which contributes to the molecule's relative robustness in solution. Lyophilized material generally retains potency for extended periods when kept cold and dry. Once reconstituted, aqueous solutions are less stable and are typically used within a defined window rather than held indefinitely at ambient temperature.
Routine handling calls for storage of the lyophilized powder at refrigerated temperatures, away from light, in a sealed container. Working solutions are often prepared in sterile water or buffer and kept cold between uses. Repeated freeze-thaw cycles are generally avoided because they can promote aggregation and loss of material. Laboratories usually record lot number, reconstitution date, and storage conditions so that any change in behavior can be traced to a specific preparation.
Reverse-phase high-performance liquid chromatography is the standard technique for assessing purity and concentration, because the peptide's hydrophobicity allows clean separation from related impurities. Mass spectrometry confirms molecular identity and detects sequence errors or truncations. Amino acid analysis and peptide mapping supply additional structural confirmation when required. Chromatographic purity values reported on certificates of analysis describe the proportion of the main peak and do not by themselves establish biological activity.
| Property | Value | Notes |
|---|---|---|
| Molecular mass | About 3.1 kDa | 28 residues, N-terminally acetylated |
| Appearance | White to off-white powder | Lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in aqueous buffers |
| Storage temperature | 2 to 8 °C | Protect from light and moisture |
| Common synonyms | Thymalfasin; Tα1 | Same peptide sequence |
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.
The molecule consists of 28 amino acid residues with an acetyl group attached to the N-terminal serine. Its sequence is acidic overall, with several glutamic and aspartic acid residues distributed along the chain and no cysteine, so disulfide bridges do not form. The peptide carries a net negative charge at physiological pH. Because the N-terminus is blocked, the intact molecule resists degradation by many aminopeptidases, which contributes to its stability in biological fluids.
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.
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.
Doris Ludlam, died 27 June 2002. Bridget Bourke, died 22 July 2002. Irene Crooks, died 20 October 2002. Ethel Hall, died 11 December 2002. All of these victims had been killed in Norris's first year of working as a nurse. Hall was a mother of one and a grandmother of two. Ludlam was a mother of two, a grandmother and great-grandmother who had worked as a nursery school teacher and fostered children for the charity Barnardo's. Wilby was a vulnerable widow. Crooks died on her 79th birthday, unable to ever open her cards or presents. Hall's son Stuart expressed his relief at Norris's conviction, stating: "I think he needs to be kept inside". He added: "He has got the knowledge to kill people and to do it discreetly. That makes him a danger to society and he must be kept inside. We hope Colin Norris never leaves prison and can never harm anyone else again." After the verdict was announced, Leeds Teaching Hospitals NHS Trust apologised to the victims' families for Norris's "disturbing" crimes, subsequently describing him as an "extremely dangerous criminal". In 2009, the Nursing and Midwifery Council struck off Norris from the medical register, taking just five minutes to come to a decision on the matter. Norris was imprisoned at HM Prison Frankland.
=== Dolls === While watching Shinjuuten no Amijima Kaname takes particular notice of the character Koharu, the doll that becomes the ideal of what Kaname thinks women should be (later to be replaced by O-hisa). The conception of womanliness that Koharu inspires in Kaname is what lies at the heart of his Madonna-Harlot conflict, and makes him attracted both to an image of the Virgin Mary and to Hollywood movie stars. He isn’t interested in real women at all, but in idealized forms of them, women who can be appreciated from afar for what they represent not for who they are. Dolls encapsulate this perfectly, being masterfully sculpted, subtle in their beauty, and silently manipulated by men.
== Education and career == Nguyen received an undergraduate degree in chemistry from Imperial College London, followed by a master's degree in health policy, planning and finance London School of Economics and from the London School of Hygiene and Tropical Medicine (LSHTM). She worked for the World Health Organization where she conducted research on medical policies. Between 1999 and 2010, she worked at GlaxoSmithKline and led the development of policies on access to medications and vaccines in the developing world. She joined Gavi in 2011, where she worked find ways to support financially sustainable vaccine programs and markets, and notably worked on strategies to supply Ebola vaccines and HPV vaccines against cervical cancer to developing countries. In October 2020, she was appointed managing director of the Office of the COVAX Facility. In 2021, Nguyen was selected as a Bloomberg New Economy Catalyst. As part of the program, Aurelia attended the annual New Economy Forum held in Singapore, and the Bloomberg New Economy Catalyst Retreat that same year.
Sources: en.wikipedia.org
September 18: In Indonesia, the Madiun Affair, an uprising carried out by the People's Democratic Front (FDR), begins led by Musso, of the Communist Party of Indonesia. The uprising ends after three months when the Indonesian army captures and kills most of the rebels. November 20: The American consul and his staff in Mukden, China, are made virtual hostages by communist forces in China. The crisis does not end until a year later, by which time U.S. relations with the new communist government in China had been seriously damaged.
[A]bout one-third of the Gratiot-area's families eventually moved to public housing, but 35 percent of the families in the area could not be traced. The best-informed city officials believed that a majority of families moved to neighborhoods within a mile of the Gratiot site, crowding into an already decaying part of the city, and finding houses scarcely better and often more overcrowded than that which they had left.
=== Molecular profiles === Protein electrophoresis (general technique—not a specific test) Western blot (general technique—not a specific test) Liver function tests Polymerase chain reaction (DNA). DNA profiling is today possible with even very small quantities of blood: this is commonly used in forensic science, but is now also part of the diagnostic process of many disorders. Northern blot (RNA) Sexually transmitted diseases
Sources: en.wikipedia.org
First line treatment for metastatic breast cancer: the MARIANNE study compares taxane (docetaxel or paclitaxel) plus trastuzumab vs T-DM1 vs T-DM1 plus pertuzumab as first-line treatment for people with HER2 positive unresectable locally advanced or metastatic breast cancer; On 19 December 2014, Roche reported the results of the MARIANNE study. Neither Kadcyla-containing treatment significantly improved progression-free survival compared to Herceptin and chemotherapy. a phase III trial for HER2+ gastric cancer compares T-DM1 to physician's choice of taxane (docetaxel or paclitaxel). On 22 October 2015, Roche and co-developer ImmunoGen disclosed that trastuzumab emtansine had failed to meet its primary endpoint in the Phase II/III GATSBY trial investigating the second line treatment of HER2-positive advanced gastric cancer. the TH3RESA study is comparing T-DM1 vs treatment of physician's choice for people with HER2 positive metastatic breast cancer previously treated with trastuzumab and lapatinib. Interim results for TH3RESA suggest a doubling of progression-free survival from three months to six months.
== As a drug target == EAAT2/GLT-1, being the most abundant subtype of glutamate transporter in the CNS, plays a key role in regulation of glutamate neurotransmission. Dysfunction of EAAT2 has been correlated with various pathologies such as traumatic brain injury, stroke, Amyotrophic lateral sclerosis (ALS), Alzheimer's disease, among others. Therefore, activators of the function or enhancers of the expression of EAAT2/GLT-1 could serve as a potential therapy for these conditions. Translational activators of EAAT2/GLT-1, such as ceftriaxone and LDN/OSU-0212320, have been described to have significant protective effects in animal models of ALS and epilepsy. In addition, pharmacological activators of the activity of EAAT2/GLT-1 have been explored for decades and are currently emerging as promising tools for neuroprotection, having potential advantages over expression activators. DL-TBOA, WAY-213,613, and dihydrokainic acid are known inhibitors of the protein, and function as excitotoxins. They can be considered a novel class of nerve agent toxins, inducing toxic levels of glutamate through transport inhibition in a manner analogous to the effect of sarin on cholinesterase. Antidotes for such a poisoning have never been formally tested for efficacy and are not readily available for medical use. Addiction to certain drugs (e.g., cocaine, heroin, alcohol, and nicotine) is correlated with a persistent reduction in the expression of EAAT2 in the nucleus accumbens (NAcc); the reduced expression of EAAT2 in this region is implicated in addictive drug-seeking behavior.
The ash content of a sample is a measure of the amount of inorganic noncombustible material it contains. The residues after a sample is completely burnt - in contrast to the ash remaining after incomplete combustion - typically consist of oxides of the inorganic elements present in the original sample. Ash is one of the components in the proximate analysis of biological materials, consisting mainly of salty, inorganic constituents. It includes metal salts which are important for processes requiring ions such as Na+ (sodium), K+ (potassium), and Ca2+ (calcium). It also includes trace minerals which are required for unique molecules, such as chlorophyll and hemoglobin. Procedures for ash content determination are similar to procedures for loss on ignition. Typically, the term ash is used for primarily organic material such as fuels and foodstuffs, while the term loss on ignition is used for primarily inorganic material such as rocks and combusted ash. A crucible can be used to determine the percentage of ash contained in a sample of material such as coal, wood, oil, rubber, plastics, foodstuffs, or any burnable material. The appropriate method for ash determination varies depending upon the type of sample analyzed. Each method may vary in parameters such as furnace temperature, residence time in the furnace, number of heating steps, and sample preparation procedures. The ISO mandates ash content determination for most foodstuffs. Examples include
Sources: en.wikipedia.org
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.
The lyophilized solid is normally held at 2 to 8 °C in a sealed, light-protected container. Dry storage limits both hydrolysis and microbial growth. Material kept this way remains stable for the shelf life stated by the supplier.