If you have been reading about thymosin alpha 1 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.
Last reviewed on 2026-01-31. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Lyophilized material is generally held at reduced temperature to slow degradation, and storage at minus twenty degrees Celsius or lower is common practice for long-term retention. Short-term working portions are often kept between two and eight degrees Celsius. Once dissolved, the peptide is less stable than the dry powder, and repeated freeze-thaw cycles are associated with loss of material and with aggregate formation. Vials are usually allowed to reach room temperature before opening so that condensation does not introduce moisture, and solutions are protected from light where practical.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography, which separates the peptide from closely related impurities and from truncated or oxidized variants. Mass spectrometry supplies the molecular mass and confirms the expected sequence length, while amino acid analysis can be used to check composition. Because the molecule has no chromophore beyond the peptide backbone, ultraviolet detection is typically performed at a low wavelength, where baseline interference from solvents and buffers is a practical concern. Water content and counter-ion content are often reported alongside purity.
| 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 |
The Canadian Penning Trap Mass Spectrometer (CPT) is one of the major pieces of experimental equipment that is installed on the ATLAS superconducting heavy-ion linac facility at the Physics Division of the Argonne National Laboratory. It was developed and operated by physicist Guy Savard and a collaboration of other scientists at Argonne, the University of Manitoba, McGill University, Texas A&M University and the State University of New York.
Half-Life 2 has an aggregate score of 96/100 on Metacritic based on 81 reviews. Sources such as 1UP, GameSpy, The Cincinnati Enquirer, The New York Times, and VideoGamer.com gave it perfect scores, and others, such as PC Gamer, IGN, GamesRadar, and Eurogamer, gave near-perfect scores. It was the fifth game to receive ten out of ten from Edge. Critics praised the graphics, physics, story and gameplay. Maximum PC awarded Half-Life 2 11 on their rating scale which normally peaks at 10, calling it "the best game ever made". In the United States, Half-Life 2's PC version sold 680,000 copies and had earned $34.3 million by August 2006. It was the country's 17th best-selling PC game between January 2000 and August 2006. It received a "Platinum" sales award from the Entertainment and Leisure Software Publishers Association (ELSPA), indicating sales of at least 300,000 copies in the United Kingdom. Forbes reported on February 9, 2011, that it had sold 12 million copies worldwide. In a review of The Orange Box, IGN stated that although Half-Life 2 has already been released through other media, the game itself is still enjoyable on a console. They also noted that the physics of Half-Life 2 are impressive despite it being a console game. However, it was noted that the graphics on the Xbox 360 version of Half-Life 2 were not as impressive as when it was released on the PC. GameSpot identified framerate problems on PlayStation 3 version.
Meanwhile, Duterte's ICC withdrawal was challenged before the Supreme Court by three petitions filed by the Philippine Coalition for the ICC, the Integrated Bar of the Philippines, and opposition senators; though the Court in March 2021 ultimately dismissed all three cases on the grounds that the petitioners were unable to establish legal standing to challenge the ICC withdrawal, the court ruled that the president has no "unbridled authority" to withdraw from treaties. The ICC, on September 16, 2021, eventually authorized a formal investigation into the war on drugs in the Philippines, focusing on crimes committed between 2016 and March 2019. In response, the Philippine government in November 2021 requested a deferral of the probe, which was suspended by the ICC to assess the request. Four days before Duterte left office, however, ICC prosecutor Karim Ahmad Khan requested the pre-trial chamber of the ICC to immediately resume the investigation after concluding that the deferral request was "not warranted". The succeeding Marcos administration initially declined to allow any ICC probe in the country due to sovereignty issues; however, due to tensions between the Duterte and Marcos political families, the Marcos administration is seen as increasingly open to cooperating with the ICC. Duterte stated he remained unfazed at the threat of arrest, saying he would rather "die first" before facing a foreign court. Salvador Panelo, who served as Duterte's chief legal counsel, alleged that Duterte's political opponents were using the ICC as a "political and propaganda apparatus".
Sources: en.wikipedia.org
Still, during the Soviet era, Jews were encouraged to admire Cossacks as the antitheses of the "parasitic" and "feeble dwellers of the shtetl." A number of Yiddish writers, including Khaim Melamud, Shmuel Gordon, Viktor Fink, and Shmuel Godiner, presented fictionalized accounts of peaceful Jewish-Cossack coexistence, while efforts were made by the pro-Soviet press to present Khmelnytsky as a heroic figure and Cossacks as liberators from the Nazis. Historiography interprets Cossackdom in imperial and colonial terms. In Ukraine, where Cossackdom represents historical and cultural heritage, some people have begun attempting to recreate the images of Ukrainian Cossacks. Traditional Ukrainian culture is often tied in with the Cossacks, and the Ukrainian government actively supports these attempts. The traditional Cossack bulava serves as a symbol of the Ukrainian presidency, and the island of Khortytsia, the origin and center of the Zaporozhian Sich, has been restored. The video game Cossacks: European Wars is a Ukrainian-made game series influenced by Cossack culture. Cossacks are also mentioned outside Europe. The Japanese anime The Doraemons, part of the larger Doraemon anime series, has a Cossack character, Dora-nichov, who is from Russia.
Brown bread, in contrast to white bread, is bread made with significant amounts of whole grain flours, usually wheat sometimes with corn and or rye flours. In some countries brown breads often get their characteristic dark color from ingredients such as molasses or coffee. In Canada, the UK, Ireland and South Africa, it is a blend of white flour and whole wheat flour. Wholemeal bread within the UK must be made solely from whole wheat flour. In New England and the Maritimes, brown bread is bread sweetened with molasses.
== Regulation == Like other drugs, botanical drugs may be sold over the counter (OTC) or by prescription only. For OTC drugs, a monograph must be created by the company that wants to market the drug and then approved by the FDA, after which it is published in the Federal Register. For prescription drugs, a New Drug Application (NDA) must be filed with and approved by the FDA; clinical data included in the NDA is gathered under an Investigational New Drug Application which the FDA also must approve before clinical testing begins. Assessment of the safety and toxicity of botanical drugs in clinical trials, and in ensuring their quality once the drug is on the market, is complicated by the nature of the raw ingredients; problems arise in identifying the correct plants to harvest, in the quality of plants harvested, in their processing, and in the stability of the active components, which are often poorly understood. The FDA relies on a combination of tests and controls to ensure the identity and quality of botanical drugs. The tests include "fingerprinting" using spectroscopy or chromatography, chemical or biological assays, and process controls on raw material collection and processing. The standards are higher for botanical drugs than for extracts or plant matter used in dietary supplements. If the substance being developed as a botanical drug has been used in traditional medicine, it may be possible to begin initial, small clinical trials without conducting extensive toxicology testing.
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.
Cool storage below freezing is usual for long-term retention, with a desiccant and protection from light. Portions are often split before first use to avoid repeated handling.