The short version of prothymosin alpha fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-03-15 and is reviewed periodically as new material appears.
Stability depends on temperature, pH, and the number of freeze-thaw events the sample has experienced. Freeze-dried material is commonly held at -20 °C or colder, while reconstituted liquid is kept cold and used within a short window. Extreme pH and prolonged light exposure can promote deamidation, oxidation, or aggregation, particularly at asparagine and methionine positions. Adsorption to container walls can lower the measured concentration of a dilute solution even when the peptide molecules themselves remain intact.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, which separates the target peptide from truncated or chemically modified byproducts. Mass spectrometry confirms the expected molecular mass and can indicate acetylation state or sequence errors. Amino acid analysis and peptide mapping supply complementary sequence-level information, while endotoxin testing is relevant for preparations intended for cell or animal work. Purity figures reported by suppliers refer to the method used and are not directly comparable across laboratories unless conditions are stated.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white lyophilized powder | Visual description varies by batch |
| Solubility | Freely soluble in water | Aqueous buffers are commonly used |
| Typical storage temperature | -20 °C or below for powder | Reconstituted liquid kept at 2-8 °C short term |
| Purity method | Reversed-phase HPLC | Value derived from peak area integration |
| Identity method | Mass spectrometry | Confirms mass and sequence integrity |
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 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 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.
Whether the free 28-residue peptide circulates in human tissue remains debated. The best-documented human source is prothymosin alpha, a larger acidic protein that carries the sequence at its N-terminus. Reports of measurable peptide levels in serum and lymphoid tissue exist, yet some of that signal may come from cross-reacting fragments or from the parent protein. Most reviews therefore treat prothymosin alpha as the established human molecule and describe independent circulation of the small peptide as an unresolved question.
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。
Maggot therapy is the intentional introduction of live, disinfected blow fly larvae (maggots) into soft tissue wounds to selectively clean out the necrotic tissue. This helps to prevent infection; it also speeds healing of chronically infected wounds and ulcers. Military surgeons since classical antiquity noticed that wounds which had been left untreated for several days, and which had become infested with maggots, healed better than wounds not so infested. Maggots secrete several chemicals that kill microbes, including allantoin, urea, phenylacetic acid, phenylacetaldehyde, calcium carbonate, proteolytic enzymes, and many others. Maggots were used for wound healing by the Maya and by indigenous Australians. More recently, they were used in Renaissance Europe, in the Napoleonic Wars, the American Civil War, and in the First and Second World Wars. It continues to be used in military medicine.
The four substrates of this enzyme are taxifolin, reduced nicotinamide adenine dinucleotide (NADH), oxygen, and a proton. Its products are dihydrogossypetin, oxidised NAD+, and water. Nicotinamide adenine dinucleotide phosphate can be used as an alternative cofactor. The enzyme is a flavin-containing monooxygenase that uses molecular oxygen as oxidant and incorporates one of its atoms into the starting material. The systematic name of this enzyme class is phenol,NADPH:oxygen oxidoreductase (2-hydroxylating). Other names in common use include phenol hydroxylase, and phenol o-hydroxylase. It uses flavin adenine dinucleotide as a second cofactor. The systematic name of this enzyme class is taxifolin,NAD(P)H:oxygen oxidoreductase (8-hydroxylating). This enzyme is also called taxifolin hydroxylase.
=== Industrial applications === Casein proteins, which are about 80% of the proteins in cow milk and between 20% and 60% in human milk. Xylanases, enzymes which degrade the linear polysaccharide xylan into xylose, thus breaking down hemicellulose, one of the major components of plant cell walls Proteases, an enzyme which catalyze proteolysis, breaking down proteins into smaller polypeptides or single amino acids. They have found applications in both the industrial (such as the food industry). and domestic settings. Whey proteins, which are about 20% of the proteins in cow milk and 60% in human milk.
== Applications == Since the early 20th century electron ionization has been one of the most popular ionization techniques because of the large number of applications it has. These applications can be broadly categorized by the method of sample insertion used. The gaseous and highly volatile liquid samples use a vacuum manifold, solids and less volatile liquids use a direct insertion probe, and complex mixtures use gas chromatography or liquid chromatography.
On 14 January, the United States Department of Energy announced that the United States had completed their first sales of Venezuelan oil valued at $500 million as part of a $2 billion deal between United States and Venezuela governments. On 15 January, Delcy Rodríguez announced that she was submitting a reform to the country's hydrocarbon law to "allow [foreign] investment flows to be incorporated into new fields, fields where no investment has ever been made and into fields where there is no infrastructure"; On 20 January, Delcy Rodríguez confirmed having received the first $300 million. She announced the money will go to the exchange market in Venezuela, the national banks and the central bank. Reuters indicated that the remaining $200 million were returned on 3 February according to anonymous United States officials. The proceeds from the sales were deposited in a Qatari bank account, preventing Venezuela's creditors from seizing them. Democrats questioned the legality of this arrangement, and criticized the lack of transparency in routing the funds. On 23 January, the first cargo of 460,000 barrels of naphtha by Vitol, necessary to deal with the heavy crude oil, arrived to Venezuela in a deal with the United States. Before that last cargo was received in December 2025 by Chevron Corporation in an agreement with the United States as the naval blockade had stopped many suppliers. On 28 January, Delcy Rodríguez announced that the United States was unfreezing various funds related to 2019 oil sanctions on Venezuela.
Sources: en.wikipedia.org
PAD3 expression has been linked to sheep wool modification. Citrullination of trichohyalin allows it to bind and cross-link keratin filaments, directing growth of the wool fiber. PAD4 regulates gene expression through histone modifications. DNA is wrapped around histones, and the histone proteins can control DNA expression when chemical groups are added and removed. This process is known as post-translational processing or post-translational modification, because it takes place on the protein after the DNA is translated. The role of post-translational processing in gene regulation is the subject of the growing field of study, epigenetics. One modification mechanism is methylation. A methyl group binds to an arginine on the histone protein, altering DNA binding to the histone and allowing transcription to take place. When PAD converts arginine to citrulline on a histone, it blocks further methylation of the histone, inhibiting transcription. The main isotype for this is PAD4, which deiminates arginines and/or monomethylated arginines on histones 3 and 4, turning off the effects of arginine methylation.
J Obstet Gynaecol Can. 40 (7): 931–934. doi:10.1016/j.jogc.2018.01.004. PMID 29921430. Lamb YN (September 2018). "Elagolix: First Global Approval". Drugs. 78 (14): 1501–1508. doi:10.1007/s40265-018-0977-4. PMC 6244606. PMID 30194661. Vercellini P, Viganò P, Barbara G, Buggio L, Somigliana E (February 2019). "Elagolix for endometriosis: all that glitters is not gold". Hum. Reprod. 34 (2): 193–199. doi:10.1093/humrep/dey368. PMID 30551159. Barra F, Scala C, Ferrero S (April 2019). "Elagolix sodium for the treatment of women with moderate to severe endometriosis-associated pain". Drugs Today. 55 (4): 237–246. doi:10.1358/dot.2019.55.4.2930713. PMID 31050692. S2CID 143434963.
30 March – It is announced that COVID-19 testing in England is to be further scaled back from April. Staff and patients in hospitals will no longer be routinely swab tested for the virus, with staff only tested if they are in contact with immunocompromised patients.
== Stages == A widely recognized heuristic for categorizing downstream processing operations divides them into four groups which are applied in order to bring a product from its natural state as a component of a tissue, cell or fermentation broth through progressive improvements in purity and concentration. Removal of insolubles is the first step and involves the capture of the product as a solute in a particulate-free liquid, for example the separation of cells, cell debris or other particulate matter from fermentation broth containing an antibiotic. Typical operations to achieve this are filtration, centrifugation, sedimentation, precipitation, flocculation, electro-precipitation, and gravity settling. Additional operations such as grinding, homogenization, or leaching, required to recover products from solid sources such as plant and animal tissues, are usually included in this group. Product isolation is the removal of those components whose properties vary considerably from that of the desired product. For most products, water is the chief impurity and isolation steps are designed to remove most of it, reducing the volume of material to be handled and concentrating the product. Solvent extraction, adsorption, ultrafiltration, and precipitation are some of the unit operations involved. Product purification is done to separate those contaminants that resemble the product very closely in physical and chemical properties. Consequently, steps in this stage are expensive to carry out and require sensitive and sophisticated equipment.
Sources: en.wikipedia.org
Cold storage slows the chemical degradation reactions that occur in solution. Lyophilized powder is more stable than reconstituted liquid and tolerates longer storage periods. Repeated temperature cycling should still be avoided because it can drive aggregation and loss of material.
Mass spectrometry is the standard confirmation of molecular mass and acetylation state. Chromatography establishes purity but does not identify the molecule on its own. The two techniques are normally applied together during verification.
No, because the reported value reflects the detection method and wavelength used, which vary between laboratories. A number stated without method details cannot be compared directly with another supplier's figure. Requesting the chromatogram and the method conditions is a common way to interpret it.
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.