deamidation raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-07-01. Anything still debated is marked as such rather than presented as settled.
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.
Laboratory supplies of the peptide usually arrive as a lyophilized powder in sealed vials. The powder is hygroscopic, so a vial should be allowed to reach room temperature before it is opened to prevent condensation on the contents. Weighing and transfer are best performed in a low-humidity environment with clean tools. Once dissolved, the solution should be mixed gently rather than vortexed, because foaming and shear can reduce recovery of the peptide.
Storage recommendations center on low temperature, dryness, and protection from repeated freezing and thawing. The intact powder is commonly held at 20 degrees below zero Celsius or colder, while a working solution is divided into single-use aliquots to limit freeze-thaw cycles. Buffered saline or phosphate-buffered saline at neutral pH is frequently used as a diluent. Light sensitivity is not well documented, yet amber vials or foil wrapping are common practice for long-term storage of peptide stocks.
Identity and purity are assessed with a small set of standard peptide methods. Reversed-phase high-performance liquid chromatography separates the main peak from truncated or oxidized species, and its area percentage is the usual purity measure. Mass spectrometry confirms the observed molecular mass against the expected value, while amino acid analysis or peptide mapping checks composition and sequence. Specifications for research-grade material are often stated as 95 percent or higher, though the exact limit depends on the supplier and the intended use.
| 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 |
Thymosin alpha 1 was identified in 1977 as a component of thymosin fraction 5, a heterogeneous preparation used in early studies of thymic function. Investigators purified the active material and determined its amino acid sequence, which enabled chemical synthesis. Work in the following decades concentrated on T-cell maturation and immune reconstitution in animals and small human cohorts. Early preparations varied in composition, so results from that period are difficult to compare with studies using defined synthetic peptide.
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Findings across trials are mixed; some report changes in selected immune markers, while others find no clear clinical benefit. Many studies are small and define outcomes differently, which limits comparison. Regulatory approval is confined to a few countries, and the compound is not an approved drug in the United States or most of Europe.
Lyophilized thymosin alpha-1 is generally stored at or below minus twenty degrees Celsius, protected from moisture and light. Short-term handling at ambient temperature is possible for dry powder, but reconstituted solutions degrade faster and are usually kept at two to eight degrees Celsius with a defined expiry of days rather than weeks. Repeated freeze-thaw cycles should be avoided because they promote aggregation and loss of potency. Exact limits depend on the formulation and should follow the supplier's documentation.
Identity and purity are normally assessed by reversed-phase high-performance liquid chromatography, which separates the peptide from related impurities and truncation products. Mass spectrometry confirms molecular mass and detects modifications such as deamidation or oxidation. Amino acid analysis and peptide mapping provide additional sequence-level confirmation. For research material, a certificate of analysis typically reports these results together with water content and counter-ion identity, since the lyophilized powder is often supplied as an acetate or trifluoroacetate salt.
presented evidence that in natural S. cerevisiae populations clonal reproduction and selfing (in the form of intratetrad mating) predominate. In nature, the mating of haploid cells to form diploid cells is most often between members of the same clonal population and out-crossing is uncommon. Analysis of the ancestry of natural S. cerevisiae strains led to the conclusion that out-crossing occurs only about once every 50,000 cell divisions. These observations suggest that the possible long-term benefits of outcrossing (e.g. generation of diversity) are likely to be insufficient for generally maintaining sex from one generation to the next. Rather, a short-term benefit, such as recombinational repair during meiosis, may be the key to the maintenance of sex in S. cerevisiae. Some pucciniomycete yeasts, in particular species of Sporidiobolus and Sporobolomyces, produce aerially dispersed, asexual ballistoconidia.
Kidder's television debut was in an episode of Wojeck aired January 16, 1968, billed as "Margaret Kidder". She very shortly afterward adopted the name Margot Kidder, which she used for the rest of her life. She then made her film debut in a 49-minute film titled The Best Damn Fiddler from Calabogie to Kaladar (1968), a drama set in a Canadian logging community, which was produced by the Challenge for Change. Kidder's 1969 appearance in the episode "Does Anybody Here Know Denny?" on the Canadian drama series Corwin earned her a Canadian Film Award for "outstanding new talent." Kidder's first major feature was the 1969 American film Gaily, Gaily, a period comedy starring Beau Bridges, in which she portrayed a prostitute. She subsequently appeared in a number of TV drama series for the CBC, including guest appearances on Adventures in Rainbow Country, and a semi-regular role as a young reporter on McQueen, and as a panelist on Mantrap, which featured discussions centered on a feminist perspective.
=== Soundtrack === The soundtrack for The Orange Box consists of music that Valve employees composed for Half-Life 2: Episode One, Half-Life 2: Episode Two, Portal, and Team Fortress 2. It also includes the original version and an exclusive remix of "Still Alive", both by Jonathan Coulton. It was released on December 21, 2007, and is sold by the official Valve Store, Amazon.com, and digital music services such as iTunes, Napster, and eMusic. A more-complete version of this soundtrack that also includes music files from Half-Life and Half-Life 2 was released on Steam as part of the Audiosurf package. "Still Alive" was subsequently released as a free downloadable song for the rhythm game Rock Band on March 31, 2008.
Sources: en.wikipedia.org
=== Other === Izon Science supplies individual and complementary parts for qEV isolation and TRPS measurements, including nanopores, TRPS calibration particles, TRPS fluid cells and qEV racks for storing qEV columns. The qEV RNA Extraction kit, manufactured for Izon Science by Norgen Biotek, is supplied to facilitate the extraction of RNA from EVs. The qEV Concentration Kit utilises Ceres NanoSciences Nanotrap® Extracellular Vesicle Particles to enable the concentration of extracellular vesicles isolated using qEV columns. The qEV RNA Extraction Kit can be used with the qEV Concentration Kit, or separately if required.
Paddy Ryder's profile on the official website of the St Kilda Football Club Paddy Ryder's playing statistics from AFL Tables Paddy Ryder at AustralianFootball.com Paddy Ryder's WAFL playing statistics at WAFLFootyFacts.net
Vicente Zambada Niebla, a high-ranking member of the Sinaloa Cartel, claimed after his arrest that he and other Sinaloa Cartel members had received immunity from U.S. agents and a virtual license to smuggle cocaine over the United States border, in exchange for intelligence about rival cartels engaged in the Mexican drug war. In October 2013, two former federal agents and an ex-CIA contractor told an American television network that CIA operatives, including Félix Rodríguez, were involved in the kidnapping and murder of DEA covert agent Enrique Camarena, because he was a threat to the agency's drug operations in Mexico. According to them, the CIA was collaborating with drug traffickers, and using its share of the profits to finance Nicaraguan Contra rebels attempting to overthrow Nicaragua's Sandinista government. A CIA spokesman responded, calling it "ridiculous" to suggest that the Agency had anything to do with the murder of a U.S. federal agent or the escape of his alleged killer.
Sources: en.wikipedia.org
The Riken team then repeated the original 209Bi + 70Zn reaction and produced a second atom of 278113 in April 2005, with a decay chain that again terminated with the spontaneous fission of 262Db. The decay data were slightly different from those of the first chain: this could have been because an alpha particle escaped from the detector without depositing its full energy, or because some of the intermediate decay products were formed in metastable isomeric states. In 2006, a team at the Heavy Ion Research Facility in Lanzhou, China, investigated the 243Am + 26Mg reaction, producing four atoms of 266Bh. All four chains started with an alpha decay to 262Db; three chains ended there with spontaneous fission, as in the 278113 chains observed at Riken, while the remaining one continued via another alpha decay to 258Lr, as in the 266Bh chains observed at LBNL. In June 2006, the JINR–LLNL collaboration claimed to have synthesised a new isotope of element 113 directly by bombarding a neptunium-237 target with accelerated calcium-48 nuclei:
== Menu and advertising == The first Taco Bell commercials premiered in 1968, featuring advertisements with Mel Blanc, Pat Harrington, and the then-host of Truth or Consequences, Bob Barker. In 1992, Johnny Cash starred in a television commercial for Taco Bell's value menu. In 1993, Taco Bell was used as product placement and plot device in the movie Demolition Man updating their currently used logo. From August 1997 to July 2000, Gidget the Chihuahua was the brand's advertising mascot, a campaign developed by TBWA. Voiced by Carlos Alazraqui, slogans included “¡Yo quiero Taco Bell!” (I want Taco Bell!), “Drop the Chalupa,” and “¡Viva Gorditas!” All became catchphrases in popular culture. In 2000, Taco Bell: Tasty Temple Challenge was released for DOS by Taco Bell as the publisher and developed by BrandGames as a kid-friendly first-person 3D action shooter with gameplay similar to that of Doom and Wolfenstein 3D in terms of combat and exploration, serving as an advertisement for the brand. The player controls Baja Bill, who explores a temple of a lost jungle civilization, battling snakes and scorpions with Taco Bell's hot and wild sauce. Food from the brand also appears in game and is used to replenish the protagonist's health.
== Species distribution == Across vertebrates, four paralogous TCAPs (TCAP-1–4) exhibit structural similarity to corticotropin-releasing hormone (CRH) and other secretin-family peptides and have been shown in rodent and non-mammalian models to exert anxiolytic-like effects, modulate glucose and energy homeostasis, and participate in broader tissue-specific signaling, highlighting TCAPs as evolutionarily conserved peptides.
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.
Aliquots are typically frozen well below zero Celsius and thawed only once, since repeated cycles promote aggregation and loss. Dilution into a neutral buffer limits degradation during short working periods, and prolonged storage at room temperature is avoided.