This is a working overview of 胸腺素α1, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-10-15. Anything still debated is marked as such rather than presented as settled.
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.
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.
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。
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。
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white lyophilized powder | Hygroscopic; let the vial equilibrate before opening |
| Solubility | Freely soluble in water and aqueous buffers | Working solutions are often prepared between 0.1 and 1 mg per mL |
| Typical storage temperature | At or below 20 degrees below zero Celsius | Desiccant and sealed vials reduce moisture uptake |
| Routine purity assay | Reversed-phase HPLC with ultraviolet detection | Result reported as percentage of total peak area |
| Identity check | Mass spectrometry with amino acid analysis | Observed mass is compared with the calculated value |
The peptide occurs naturally in thymic tissue and has been detected in serum and other biological fluids. Reported concentrations are low, and reliable measurement generally requires immunoassay or mass spectrometry with an enrichment step. It is released from a larger precursor, prothymosin alpha, by proteolytic cleavage, although the enzymes involved are not fully characterized. Whether circulating levels reflect thymic output specifically remains an open question.
Thymosin alpha 1 is a 28-amino-acid peptide first isolated from thymosin fraction 5, a bovine thymic extract. Its sequence begins with an acetylated serine residue and carries a high proportion of acidic residues, so the molecule has a net negative charge near neutral pH. Despite the shared name, it is unrelated in sequence to the thymosin beta family. Synthetic material prepared by solid-phase peptide synthesis is identical in sequence to the natural peptide.
Several names appear in the literature for this peptide, including thymalfasin and the abbreviation T-alpha-1. Naming conventions differ among research articles, regulatory documents, and supplier catalogs, which complicates literature searches. Both synthetic and recombinant production routes yield a peptide with the same 28-residue sequence as the thymic isolate. Because the thymosin label also covers unrelated peptides, sources should be compared by sequence rather than by name alone.
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.
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.
The peptide lacks cysteine, methionine, and tryptophan, so disulfide scrambling and sulfur oxidation are not major degradation routes. Instead, aspartate residues can undergo isomerization or cyclization to succinimide intermediates, generating isoaspartate variants. Hydrolysis of peptide bonds also occurs slowly in solution. These changes may reduce biological activity even when the main peak remains detectable. Stability studies therefore track both potency and the appearance of related substances.
Lyophilized thymosin alpha 1 is typically stored refrigerated at 2 to 8 degrees Celsius and kept away from light. Reconstituted solutions are less stable and are usually used promptly after preparation. Repeated freeze-thaw cycles are avoided because they can promote aggregation and loss of activity. The peptide adsorbs to some plastic and glass surfaces, so a carrier protein is often added to dilute working solutions. Manufacturer instructions and published protocols both govern handling.
Identity and purity testing for thymosin alpha 1 relies mainly on reversed-phase high-performance liquid chromatography and mass spectrometry. Chromatography separates the parent peptide from truncated or modified variants, while mass spectrometry confirms the expected molecular mass. Amino acid analysis and peptide mapping provide additional sequence confirmation. Counterion content, water content, and residual solvents are measured separately as part of specification testing. No single method captures every attribute, so laboratories combine several techniques.
Biologically, the peptide is studied mainly in the context of immune cell development and regulation. It is produced in the thymus and in several other tissues, and it appears to influence the maturation and activity of T cells and other immune populations. Laboratory work describes effects on cytokine production, on the balance between T cell subsets, and on the function of dendritic cells. Much of this evidence comes from cell culture and animal models, so the extent to which the same pathways operate in humans remains an open question.
Clinical interest has centered on chronic viral hepatitis, on immune restoration in various conditions, and on use as an adjuvant intended to improve responses to vaccines. Trials have reported mixed results, and regulatory status differs sharply between countries; in some places it is a prescription product, while elsewhere it is sold without an approved therapeutic indication. Because published studies vary widely in design, population, and endpoints, comparisons across them are difficult and no single conclusion covers the whole literature.
Thymosin alpha 1 is a short peptide of 28 amino acid residues that derives from the amino terminal region of a larger precursor protein known as prothymosin alpha. The peptide carries an acetyl group on its first residue and contains no disulfide bonds or carbohydrate chains. Its sequence is highly conserved across mammalian species, which is one reason laboratories treat it as a molecule with a defined and reproducible structure rather than a variable tissue extract. The name follows an early naming convention for thymus-derived fractions and does not imply that the peptide acts as a hormone in the classical endocrine sense.
== Etymology == The generic name Datura is taken from Hindi धतूरा dhatūra "thorn-apple", ultimately from Sanskrit धत्तूर dhattūra "white thorn-apple" (referring to Datura metel of Asia). In the Ayurvedic text Sushruta Samhita, different species of Datura are also referred to as kanaka and unmatta. Dhatura is offered to Lord Shiva in Hinduism. Record of this name in English dates back to 1662. Nathaniel Hawthorne refers to one type in The Scarlet Letter as "apple-Peru". In Mexico, its common name is toloache (also spelled tolguacha), which derives from the Nahuatl tolohuaxihuitl, meaning "the plant with the nodding head" (in reference to the nodding seed capsules of Datura species belonging to section Dutra of the genus). The term "Jimsonweed" is said to come from the American colony Jamestown. In Jamestown datura was common, and was referred to as "Jamestown-Weed" by one Virginian, Robert Beverley Jr. This then turned into the term "Jimsonweed".
=== Sports === The regulation of modafinil as a doping agent has been controversial in sport since several American athletes tested positive for the substance. Some athletes who used modafinil protested that it was not on the prohibited list at the time of their offenses. However, the World Anti-Doping Agency (WADA) maintains that modafinil was related to already-banned substances. The Agency added modafinil to its list of prohibited substances on August 3, 2004, ten days before the start of the 2004 Summer Olympics. Several athletes across track and field, cycling, basketball, and rowing have tested positive for modafinil and faced sanctions, with some cases resulting in stripped medals and bans. The BALCO scandal brought to light an unsubstantiated (but widely published) account of Major League Baseball's all-time leading home-run hitter Barry Bonds' supplemental chemical regimen that included modafinil in addition to anabolic steroids and human growth hormone.
the non-standard amino acid to encode, an unused codon to adopt, a tRNA that recognizes this codon, and a tRNA synthetase that recognizes only that tRNA and only the non-standard amino acid. Expanding the genetic code is an area of research of synthetic biology, an applied biological discipline whose goal is to engineer living systems for useful purposes. The genetic code expansion enriches the repertoire of useful tools available to science. In May 2019, researchers, in a milestone effort, reported the creation of a new synthetic (possibly artificial) form of viable life, a variant of the bacteria Escherichia coli, by reducing the natural number of 64 codons in the bacterial genome to 61 codons (eliminating two out of the six codons coding for serine and one out of three stop codons) – of which 59 used to encode 20 amino acids.
Throughout the Cold War, Iraq had been an ally of the Soviet Union, and there was a history of friction between Iraq and the United States. The US was concerned with Iraq's position on Israeli–Palestinian politics. The US also disliked Iraqi support for Palestinian militant groups, which led to Iraq's inclusion on the developing US list of State Sponsors of Terrorism in December 1979.
=== Competitive === A third use of ELISA is through competitive binding. The steps for this ELISA are somewhat different from the first two examples: Unlabeled antibody is incubated in the presence of its antigen (sample).
Sources: en.wikipedia.org
Boehringer Ingelheim Austria has validated a method with cGMP (commercial good manufacturing practices) for production of pharmaceutical-grade DNA plasmids. They are able to process 200L of fermentation broth on an 800mL monolith. At BIA Separations, processing time of the tomato mosaic virus decreased considerably from the standard five days of manually intensive work to equivalent purity and better recovery in only two hours with a monolith column. Other viruses have been purified on monoliths as well. Affinity monoliths have also been applied to the isolation of nanoscale particles from human plasma. Tandem monolithic disks functionalized with chondroitin-6-sulfate and anti-apolipoprotein B-100 antibodies enabled the selective isolation of low-density lipoprotein in less than 30 minutes, while a monolith carrying an anti-CD61 antibody isolated platelet-derived extracellular vesicles in 19 minutes. Monolithic disks carrying antibodies against apoB-100, CD9, or CD61 were subsequently coupled online to asymmetric flow field-flow fractionation, allowing automated isolation and size fractionation of lipoproteins and extracellular-vesicle subpopulations. Extracellular-vesicle fractions obtained using these monolith-based systems have also been characterized by Raman spectroscopy and comprehensive two-dimensional gas chromatography, and used in quartz crystal microbalance studies of binding between extracellular-vesicle subpopulations and affinity ligands.
Narrated by Alun Lewis, directed by Gary Leach, produced by Geoff Deehan, produced by Sandlin Productions 24 November The Dyslexic Engineer, about Ben Bowlby, born on 2 November 1966; his VS91 car at Snetterton Circuit, with a Vauxhall Astra engine, with footage mostly from the end of the earlier documentary in September 1990; his studies at the Polytechnic of East London; Richard Bowlby, his father from Hampstead, who also realised that he was dyslexic; Rosalind Rathouse, his former remedial teacher; Roy Greenfield, a retired maths teacher from King Alfred School, London, who believed that perhaps people would adapt to mathematics more if the subject was taught later in life, as people are often put off the subject at secondary school; Ben gained nine O-levels but couldn't acquire Mathematics A-level above grade E after, two attempts; Xenia Bowlby; his polytechnic course tutor, Alan Slawson, and limited-slip differentials; his car raced in the Clubman (racing car class); he was sponsored by Ripspeed clothing and Spax Performance shock absorbers; Eric Broadly of Lola Cars; he joined Lola Cars in October 1991; he had attempted to gain a place at Lancaster University to study Engineering; Mike Blanchet of Lola Cars; empirical research in designing and building motor racing cars; Mark Williams, head of Formula 3000 at Lola Cars. Narrated by Ian Holm, produced by Michael Proudfoot, directed by Patrick Uden, made by Uden Associates.
methane CH4 – one carbon and 4 hydrogen ethane C2H6 – two carbon and 6 hydrogen propane C3H8 – three carbon and 8 hydrogen butane C4H10 – four carbon and 10 hydrogen pentane C5H12 – five carbon and 12 hydrogen hexane C6H14 – six carbon and 14 hydrogen heptane C7H16 – seven carbons and 16 hydrogen octane C8H18 – eight carbons and 18 hydrogen The first four names were derived from methanol, ether, propionic acid and butyric acid. Alkanes with five or more carbon atoms are named by adding the suffix -ane to the appropriate numerical multiplier prefix with elision of any terminal vowel (-a or -o) from the basic numerical term. Hence, pentane, C5H12; hexane, C6H14; heptane, C7H16; octane, C8H18; etc. The numeral prefix is generally Greek; however, alkanes with a carbon atom count ending in nine, for example nonane, use the Latin prefix non-.
Following the approval of eteplirsen, two other drugs of a similar kind, golodirsen and viltolarsen received provisional approval from the FDA for the treatment of people with a confirmed mutation of the dystrophin gene that is amenable to exon 53 skipping as well as casimersen for exon 45 skipping.
== External links == Clinical trial number NCT02896192 for "Setmelanotide for the Treatment of Early-Onset POMC Deficiency Obesity" at ClinicalTrials.gov Clinical trial number NCT03287960 for "Setmelanotide for the Treatment of LEPR Deficiency Obesity" at ClinicalTrials.gov
Sources: en.wikipedia.org
=== Colorimetric biosensors === Biosensors are attached to a substance of interest. Normally, this substance would not be able to absorb light, but with the attached biosensor, light can be absorbed and emitted on a spectrophotometer. Additionally, biosensors that are fluorescent can be viewed with the naked eye. Some fluorescent biosensors also have the ability to change color in changing environments (ex: from blue to red). A researcher would be able to inspect and get data about the surrounding environment based on what color he or she could see visibly from the biosensor-molecule hybrid species. Colorimetric assays are normally used to determine how much concentration of one species there is relative to another.
7 December Storm Darragh: Hundreds of thousands are left without power, while travel is disrupted and many planned events are called off, as winds of up to 93 mph (150 km/h) hit much of the UK, along with heavy rain. A rare red weather warning is in place in Wales and south-west England, meaning the storm poses a risk to life. The deaths of two men are reported, in Birmingham and Lancashire, due to trees falling on vehicles. A 61-year-old Elizabeth line worker dies following a serious assault at Ilford railway station on 4 December. A 28-year-old man is charged with grievous bodily harm, affray, and possession of a prohibited offensive weapon. 8 December Prime Minister Sir Keir Starmer welcomes the Fall of the Assad regime in Syria, which he describes as "barbaric", and calls for the restoration of "peace and stability". Emma Pinchbeck, the new chief executive of the UK government's Climate Change Committee, says the UK is "not ready" for the kind of extreme weather brought by Storm Darragh. Prince William helps to serve lunch at The Passage, a London-based homeless charity he first visited with his mother as a boy. 9 December – The UK pauses asylum claims from Syrian refugees following the overthrow of Bashar al-Assad. 10 December The UK government recommends a 2.8% pay rise for public sector workers from April 2025. In response, the Unison trade union describes the offer as "barely above the cost of living". King Charles III presents the first Elizabeth Emblems, recognising public servants such as police officers and firefighters who died while on duty.
=== Variation === The sternalis muscle may be a variant form of the pectoralis major or the rectus abdominis. Some fibers are occasionally connected with the costoxiphoid ligaments, and the side of the xiphoid process.
== Pharmacokinetics == Most of the research on creatine so far has focused on its pharmacological properties. There has been less research into the pharmacokinetics of creatine. Studies have not established pharmacokinetic parameters for clinical usage of creatine such as volume of distribution, clearance, bioavailability, mean residence time, absorption rate, and half life. A clear pharmacokinetic profile would need to be established prior to determine optimal clinical dosing.
== Clinical effects == Kynurenine protects the eye by absorbing UV light, especially in the UVA region (315–400 nm). Kynurenine is present in the lens and retina as one of multiple tryptophan derivatives produced in the eye, including 3-hydroxykynurenine, that together provide UV protection and aid in enhancing visual acuity. The use of kynurenine as a UV filter is consistent with its photostability and low photosensitization, owing to its efficient relaxation from the UV-induced excited state. The concentration of this UV filter decreases with age, and this loss of free kynurenine and the concomitant formation of relatively more photosensitizing kynurenine derivatives and kynurenine-protein conjugates may contribute to the formation of cataracts. Evidence suggests that increased kynurenine production may precipitate depressive symptoms associated with interferon treatment for hepatitis C. Cognitive deficits in schizophrenia are associated with imbalances in the enzymes that break down kynurenine. Blood levels of kynurenine are reduced in people with bipolar disorder. Kynurenine production is increased in Alzheimer's disease and cardiovascular disease where its metabolites are associated with cognitive deficits and depressive symptoms. Kynurenine is also associated with tics. Myokines regulate its metabolism. Kynurenine has also been identified as one of two compounds that makes up the pigment that gives the goldenrod crab spider its yellow color.
Sources: en.wikipedia.org
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.
Research material is commonly offered at 95 percent purity or above by chromatographic area, with some suppliers listing 98 percent. Higher grades usually carry a higher price and are chosen when the assay is sensitive to trace impurities.
Mass spectrometry is the standard check, often paired with amino acid analysis or peptide mapping. A chromatographic retention time alone is generally considered insufficient for structural confirmation.
它不是经典的内分泌激素，而是一种免疫调节肽。其作用主要通过局部免疫细胞间的信号传递实现，而非经血液循环作用于远隔器官。