lyophilization is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2025-11-27. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Immunological studies connect the peptide to multiple parts of the immune response. It has been reported to engage Toll-like receptor signaling, to promote dendritic cell maturation, and to influence the balance of T helper cell subsets. Changes in natural killer cell activity and in cytokine release appear in cell culture and animal models. These observations describe broad immunomodulatory behavior rather than a single defined receptor target, and the primary molecular interaction has not been settled.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Amino acid length | 28 residues | Single chain with an acetylated N-terminus |
| Molecular mass | Approximately 3,108 Da | Small shifts occur with counter-ion and water content |
| Isoelectric point | Around 3.5 | Low value follows from the many acidic residues |
| Parent molecule | N-terminal region of prothymosin alpha | Free circulating form in humans is not firmly established |
| Common synonyms | Thymalfasin; T alpha 1 | Older literature also uses the full spelled-out form |
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。
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.
On November 19, 2019, a lawsuit was filed by a vegan from Atlanta, Georgia, against Burger King for allegedly failing to clearly disclose that Impossible Whopper burgers were heated on the same grill as their beef burgers. The lawsuit was dismissed. On March 28, 2022, a lawsuit was filed against Burger King, alleging the fast food chain falsely advertised the Whopper to "look about 35% bigger in its advertising than it is in reality". On May 5, 2025, Federal Judge Roy Altman allowed the case to proceed, stating the claims may reasonably suggest consumers were misled and that Florida law permits such misrepresentation suits without a special relationship. Burger King argued that differences between ads and actual burgers are typical of handmade food and standard marketing practices.
=== Submachine guns === Sten – Used very early on, replaced by the early 1960s. Suppressed versions remained in use into the late 1960s. Lanchester submachine gun - Royal Navy issue into the 1970s Sterling submachine gun – Main submachine gun, adopted in 1953. Suppressed L34A1 version adopted in 1967. MAC-10 - Special forces issue until the early 1980s, also used by 14 Intelligence Company. 9x19mm model. Heckler & Koch MP5 - Special forces issue from the late 1970s; MP5A3, MP5SD3, and MP5K. MP5K also used by 14 Intelligence Company.
== Honors and awards == American Heart Association Basic Research Prize (1993) William B. Coley Award for Distinguished Research in Basic and Tumor Immunology (1995) Member of the National Academy of Sciences (1996) Member of the National Academy of Medicine (2023) Fellow of the American Academy of Arts and Sciences (2001) Crafoord Prize in Polyarthritis (2004) Guggenheim Fellowship (2004) Fellow of the American Association for the Advancement of Science (2013) AAI-Life Technologies Meritorious Career Award (now AAI-Thermo Fisher Meritorious Career Award), American Association of Immunologists (2014) Henry M. Stratton Medal, American Society of Hematology (2014) Canada Gairdner International Award (2019) Albert Lasker Award for Basic Medical Research (2022) Robert Koch Prize (2023) Biophysical Society Founders Award (2022) The Protein Society Stein & Moore Award (2025) Fellow of the National Academy of Inventors (2025) Included in Forbes’ 250: America’s Greatest Innovators list (2026) Selected to receive the American Society for Biochemistry and Molecular Biology’s Bert and Natalie Vallee Award in Biomedical Science (2027) He was a Phi Beta Kappa graduate from the University of California, Berkeley.
== Plutonium-240 as an obstacle to nuclear weapons == 240Pu undergoes spontaneous fission at a small but significant rate (5.8×10−6%). The presence of 240Pu limits the plutonium's use in a nuclear bomb, because a neutron from spontaneous fission starts the chain reaction prematurely, causing an early release of energy that disperses the core before full implosion is reached. This prevents most of the core from participation in the chain reaction and reduces the bomb's yield. Plutonium consisting of more than about 90% 239Pu is called weapons-grade plutonium; plutonium from spent nuclear fuel from commercial power reactors generally contains at least 20% 240Pu and is called reactor-grade plutonium. However, modern nuclear weapons use fusion boosting, which mitigates the predetonation problem; if the pit can generate a nuclear weapon yield of even a fraction of a kiloton, which is enough to start deuterium–tritium fusion, the resulting burst of neutrons will fission enough plutonium to ensure a yield of tens of kilotons. Contamination due to 240Pu is the reason plutonium weapons must use the implosion method. Theoretically, pure 239Pu could be used in a gun-type bomb, but achieving this level of purity is prohibitively difficult. 240Pu contamination has proven a mixed blessing. While it created delays and headaches during the Manhattan Project because of the need to develop implosion technology, those same difficulties are a barrier to nuclear proliferation. Implosion bombs are also inherently more efficient and less prone to accidental detonation than are gun-type bombs.
In 1987, Yates purchased Temple Gym on Temple Street in Birmingham. In 2006, he franchised four additional Temple Gym locations, three of which are in the UK. As of 2020, only the original Birmingham gym is still in operation; it later relocated from Temple Street to the city's Jewellery Quarter. In 1994, Yates and bodybuilding brothers Mike and Ray Mentzer formed the California-based company Heavy Duty Inc., which marketed athletic apparel and bodybuilding books. In 1998, he partnered with Kerry Kayes to form the bodybuilding supplement company CNP Professional, which marketed a "Dorian Yates Approved" product line in the U.S. He left the company in 2006 to form his own company, Dorian Yates Ultimate Formulas, which offers a line of protein and weight-gain supplements. Yates started a second company in 2010 called EU Peptides, which sells peptide hormones and other pro-hormone supplements. He left this company in 2012, having founded a third company called DY Nutrition in 2011; it specializes in pre-workout formulas, has released several training DVDs, and offers a line of workout related supplements endorsed by Yates.
Sources: en.wikipedia.org
In 1959 Hahn co-founded in Berlin the Federation of German Scientists (VDW), a non-governmental organisation, which has been committed to the ideal of responsible science. The members of the Federation feel committed to taking into consideration the possible military, political, and economic implications and possibilities of atomic misuse when carrying out their scientific research and teaching. With the results of its interdisciplinary work the VDW not only addresses the general public, but also the decision-makers at all levels of politics and society. Right up to his death, Otto Hahn never tired of warning of the dangers of the nuclear arms race between the great powers and of the radioactive contamination of the planet. Lawrence Badash wrote:
=== Cell migration === Cell migration is essential for the formation of granulation tissue. The early stage of granulation tissue is dominated by a HA-rich extracellular matrix, which is regarded as a conducive environment for the migration of cells into this temporary wound matrix. HA provides an open hydrated matrix that facilitates cell migration, whereas, in the latter scenario, directed migration and control of related cell mechanisms are mediated via the specific cell interaction between HA and cell surface HA receptors. It forms links with several protein kinases associated with cell locomotion, for example, extracellular signal-regulated kinase, focal adhesion kinase, and other non-receptor tyrosine kinases. During fetal development, the migration path through which neural crest cells migrate is rich in HA. HA is closely associated with the cell migration process in granulation tissue matrix, and studies show that cell movement can be inhibited, at least partially, by HA degradation or blocking HA receptor occupancy. By providing the dynamic force to the cell, HA synthesis has also been shown to associate with cell migration. Basically, HA is synthesized at the plasma membrane and released directly into the extracellular environment. This may contribute to the hydrated microenvironment at sites of synthesis, and is essential for cell migration by facilitating cell detachment.
== Etymology == The proposed name for the toxin is U7-ctenitoxin-Pn1a. Here, 'ctenitoxin' refers to toxins found in the venom of spiders from the Ctenidae family. 'Pn' is an acronym for Phoneutria nigriventer, referring to the genus and species of the animal it was isolated from. A commonly used alternative name for U7-CNTX-Pn1a is PnTx3-5, which is an acronym for Phoneutria nigriventer Toxin 3–5. Here, 3 refers to it being part of the third toxic protein fraction that was isolated from the venom using a technique involving a combination of gel filtration and reverse phase fast protein liquid chromatography. Similarly, 5 refers to it being the fifth peptide that was separated from this fraction through reverse phase and ion-exchange high-performance liquid chromatography.
=== Broadcasters === Robert Siegel (1968), host of All Things Considered on National Public Radio Jim Gardner (1970), anchor for WPVI-TV news in Philadelphia Christopher Kimball (1973), celebrity chef, editor-in-chief of Cook's Illustrated and host of America's Test Kitchen George Whipple III (1977), lawyer and society correspondent for NY1 Pimm Fox (1982), Bloomberg Radio and Bloomberg Television anchorman Fred Katayama (1982), anchor on Reuters Television James Rubin (1982), Sky News anchorman; former assistant secretary of state for public affairs in the Clinton Administration; spokesman for the presidential campaigns of Wesley Clark and John Kerry; husband of Christiane Amanpour George Stephanopoulos (1982), ABC News personality; senior advisor to U.S.
Sources: en.wikipedia.org
Post-translational modifications can incorporate more complex, large molecules into the folded protein structure. One common example of this is glycosylation, the addition of a polysaccharide molecule, which is widely considered to be most common post-translational modification. In glycosylation, a polysaccharide molecule (known as a glycan) is covalently added to the target protein by glycosyltransferases enzymes and modified by glycosidases in the endoplasmic reticulum and Golgi apparatus. Glycosylation can have a critical role in determining the final, folded 3D structure of the target protein. In some cases glycosylation is necessary for correct folding. N-linked glycosylation promotes protein folding by increasing solubility and mediates the protein binding to protein chaperones. Chaperones are proteins responsible for folding and maintaining the structure of other proteins. There are broadly two types of glycosylation, N-linked glycosylation and O-linked glycosylation. N-linked glycosylation starts in the endoplasmic reticulum with the addition of a precursor glycan. The precursor glycan is modified in the Golgi apparatus to produce complex glycan bound covalently to the nitrogen in an asparagine amino acid. In contrast, O-linked glycosylation is the sequential covalent addition of individual sugars onto the oxygen in the amino acids serine and threonine within the mature protein structure.
==== Elimination ==== Atomoxetine and its metabolites are eliminated mainly via excretion into urine. Less than 3% of atomoxetine is excreted unchanged in urine regardless of CYP2D6 status, indicating extensive metabolism. In CYP2D6 extensive metabolizers, who are considered to have normal CYP2D6 activity, more than 96% of a dose of radiolabeled atomoxetine is excreted in urine within 24 hours and 1 to 2% is excreted in feces. Conversely, in CYP2D6 poor metabolizers, excretion is slower, with only 27% excreted after 24 hours, a majority of radioactivity excreted within 72 hours, and ~144 hours required for full excretion. In addition, only 80% of radioactivity is excreted in urine while 13 to 22% is excreted in feces in CYP2D6 poor metabolizers. The major excreted metabolite of atomoxetine is 4-hydroxyatomoxetine glucuronide, which accounts for >80% of the dose in urine but <17% of the dose in feces. The fractions excreted in urine as 4-hydroxyatomoxetine and 4-hydroxyatomoxetine glucuronide account for 86% of a dose in CYP2D6 extensive metabolizers, but only 40% in CYP2D6 poor metabolizers. CYP2D6 poor metabolizers excrete greater amounts of minor atomoxetine metabolites, namely N-desmethylatomoxetine and 2-hydroxymethylatomoxetine and their conjugates, than extensive metabolizers. The elimination half-life of atomoxetine is 4.5 to 5.3 hours in CYP2D6 extensive metabolizers. However, in CYP2D6 poor metabolizers, the half-life of atomoxetine is 19 to 21.6 hours, or about 4-fold longer in comparison.
On the broader subject of Communism, Lindemann wrote that Peukert's book was flawed by what the reviewer considered his moral blind spot, writing that for Peukert fascism was "a convenient absolute evil; anti-fascism, however flawed in its particulars is thus in some ultimate sense heroic". Lindemann wrote that "the author [Peukert] appears to consider it absurd to suggest the KPD and the NSDAP morally resembled each other. Yet Stalinism in the 1930s was at least as brutish in form as Hitlerism and was responsible, at least until 1939, for many more deaths, indeed for organized murder on an unparalleled scale. The KPD enthusiastically associated itself with the nightmarish inhumanities of Stalin's rule". Lindemann ended his review that Peukert's approach in considering Communist resistance in Nazi Germany to be "heroic" was wrong as the subject of "Communist heroism" in Nazi Germany was more morally nuanced than what Peukert would consider.
Sources: en.wikipedia.org
It is usually described as an immunomodulatory peptide rather than a classic circulating hormone. No endocrine gland is known to release it as a primary secretory product, and its measured presence in blood is not firmly established.
Prothymosin alpha is a much larger acidic protein, roughly 111 to 113 residues long, and the thymosin alpha-1 sequence matches its N-terminal region. The small peptide is therefore best understood as a fragment of that parent protein rather than a separate gene product.
Trials and clinical reports have examined chronic hepatitis B and C, use as a vaccine adjuvant, and supportive treatment in some immunodeficiency and oncology settings. Results vary by indication, and regulatory approval differs between countries.
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.