immunomodulatory peptide raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-03-15 and is reviewed periodically as new material appears.
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。
Thymosin alpha-1 is a synthetic peptide of 28 amino acids whose sequence matches the amino-terminal region of prothymosin alpha. The chain is acetylated at its first residue and contains one disulfide bridge between two cysteine residues, which folds the molecule into a compact loop. Its molecular formula, C129H215N33O55, corresponds to a monoisotopic mass of roughly 3,106 daltons. Material used in laboratories is made by solid-phase synthesis rather than isolated from animal tissue.
Early work on thymic extracts in the 1960s described a heat-stable acidic fraction containing many polypeptides. Separation of that mixture yielded individual components, and thymosin alpha-1 was named as one of them on the basis of assays for T-cell activity. The first preparations came from calf thymus, while subsequent research and clinical material has been chemically synthesized. Nomenclature in older papers is inconsistent, and the same peptide sometimes appears under different designations, which complicates literature searches.
Most published studies on thymosin alpha-1 report changes in immune measurements rather than clinical outcomes, and findings differ across designs and populations. Whether the peptide signals through one defined receptor or through several less specific interactions remains an open question. Its reported circulation half-life of a few hours complicates comparison of dosing schedules across trials. Mechanistic claims are frequently drawn from isolated cell cultures, and how far those results extend to whole organisms is unresolved.
| Property | Value | Notes |
|---|---|---|
| 化学分类 | 线性肽 | 由28个氨基酸组成 |
| 分子量 | 约3108 Da | 合成版本一致 |
| 外观 | 白色至类白色粉末 | 冻干品 |
| 溶解度 | 易溶于水 | 微溶于有机溶剂 |
| 储存温度 | -20°C（冻干） | 溶解后2-8°C |
Thymosin alpha-1 is a 28-residue peptide first isolated from thymus tissue in the 1970s. It corresponds to the N-terminal portion of thymosin beta-4, from which it is cleaved in vivo. The peptide carries an acetyl group at its N-terminus, a modification that affects its charge and stability. Synthetic material produced by solid-phase peptide synthesis is chemically identical to the natural fragment and is the form used in research and clinical studies.
Laboratory work indicates that the peptide acts on cells of both the innate and adaptive immune systems. Reported effects include signalling through Toll-like receptors on dendritic cells, enhanced T-cell maturation, and increased natural killer cell activity. These actions are described largely from cell-culture and animal experiments, and the precise receptor-level events remain incompletely defined. Studies in humans have generally measured immune markers rather than a single defined molecular target. The resulting picture remains partly descriptive.
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Results across trials have been mixed, and several studies were small or conducted under differing protocols. Regulatory status varies by country, and the compound is not approved in every jurisdiction where it is studied. Evidence for any single indication should be read with attention to sample size and endpoint choice.
Thymosin alpha-1 is a synthetic peptide of 28 amino acids, corresponding to the N-terminal fragment of prothymosin alpha. Its sequence begins with acetylation at the N-terminus, a modification that affects stability and receptor interaction. The peptide is acidic, with a calculated isoelectric point near 4.2, and carries no disulfide bonds, so its secondary structure is largely flexible in solution. Molecular mass is approximately 3108 daltons. The native form was first isolated from bovine thymus tissue, while pharmaceutical material is produced by solid-phase peptide synthesis.
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.
== Functions of aquatic plants == One of the largest aquatic plants in the world is the Bolivian waterlily, which holds the Guinness World Record of having the largest undivided leaf at 3.2 m (10 ft 6 in) diameter; the smallest is the rootless duckweed, which is only 1 mm (0.039 in) across. Many small animals use aquatic plants such as duckweeds and lily pads for spawning or as protective shelters against predators both from above and below the water surface. Aquatic plants are important primary producers and are the basis of food web for many aquatic fauna, especially wetland species. They compete with phytoplanktons for excess nutrients such as nitrogen and phosphorus, thus reducing the prevalence of eutrophication and harmful algal blooms, and have a significant effect on riparian soil chemistry as their leaves, stems and roots slow down the water flow, capture sediments and trap pollutants. Excess sediment will settle into the stream bed due to the reduced flow rates, and some aquatic plants also have symbiotic microbes capable of nitrogen fixation and breaking down the pollutants trapped and/or absorbed by the roots. Historically, aquatic plants have been less studied than terrestrial plants, and management of aquatic vegetation has become an increasingly interested field as means to reduce agricultural pollution of water bodies.
One NADH molecule is produced by the enzyme glutamate dehydrogenase in the conversion of glutamate to ammonium and α-ketoglutarate. Glutamate is the non-toxic carrier of amine groups. This provides the ammonium ion used in the initial synthesis of carbamoyl phosphate. The fumarate released in the cytosol is hydrated to malate by cytosolic fumarase. This malate is then oxidized to oxaloacetate by cytosolic malate dehydrogenase, generating a reduced NADH in the cytosol. Oxaloacetate is one of the keto acids preferred by transaminases, and so will be recycled to aspartate, maintaining the flow of nitrogen into the urea cycle. We can summarize this by combining the reactions:
Generally speaking, if a member state has laws or practices that directly discriminate against imports (or exports under TFEU article 35) then it must be justified under article 36. The justifications include public morality, policy or security, "protection of health and life of humans, animals or plants", "national treasures" of "artistic, historic or archaeological value" and "industrial and commercial property". In addition, although not clearly listed, environmental protection can justify restrictions on trade as an overriding requirement derived from TFEU article 11. More generally, it has been increasingly acknowledged that fundamental human rights should take priority over all trade rules. So, in Schmidberger v Austria the Court of Justice held that Austria did not infringe article 34 by failing to ban a protest that blocked heavy traffic passing over the A13, Brenner Autobahn, en route to Italy. Although many companies, including Mr Schmidberger's German undertaking, were prevented from trading, the Court of Justice reasoned that freedom of association is one of the 'fundamental pillars of a democratic society', against which the free movement of goods had to be balanced, and was probably subordinate. If a member state does appeal to the article 36 justification, the measures it takes have to be applied proportionately.
Sources: en.wikipedia.org
In 2005, ten countries accounted for the majority of the world's concentrated uranium oxides: Canada (27.9%), Australia (22.8%), Kazakhstan (10.5%), Russia (8.0%), Namibia (7.5%), Niger (7.4%), Uzbekistan (5.5%), the United States (2.5%), Argentina (2.1%) and Ukraine (1.9%). In 2008, Kazakhstan was forecast to increase production and become the world's largest supplier of uranium by 2009; Kazakhstan has dominated the world's uranium market since 2010. In 2021, its share was 45.1%, followed by Namibia (11.9%), Canada (9.7%), Australia (8.7%), Uzbekistan (7.2%), Niger (4.7%), Russia (5.5%), China (3.9%), India (1.3%), Ukraine (0.9%), and South Africa (0.8%), with a world total production of 48,332 tonnes. Most uranium was produced not by conventional underground mining of ores (29% of production), but by in-situ leaching (66%). In the late 1960s, UN geologists discovered major uranium deposits and other rare mineral reserves in Somalia. The find was the largest of its kind, with industry experts estimating the deposits at over 25% of the world's then known uranium reserves of 800,000 tons. The ultimate available supply is believed to be sufficient for at least the next 85 years, though some studies indicate underinvestment in the late twentieth century may produce supply problems in the 21st century. Uranium deposits seem to be log-normal distributed. There is a 300-fold increase in the amount of uranium recoverable for each tenfold decrease in ore grade. In other words, there is little high grade ore and proportionately much more low grade ore available.
== Applications == Synthetic biology initiatives frequently aim to redesign organisms so that they can create a material, such as a drug or fuel, or acquire a new function, such as the ability to sense something in the environment. Examples of what researchers are creating using synthetic biology include:
Mick Anglo (born Maurice Anglowitz, 19 June 1916 – 31 October 2011) of Russian Jewish ancestry, was a British comic book writer, editor and artist, as well as an author. He is best known for creating the superhero Marvelman, later known as Miracleman, a character later revived in 1982 in a dark, post-modern reboot by writer Alan Moore, with later contributions by Neil Gaiman. Lisa Appignanesi (born 4 January 1946) writer, novelist, campaigner for free expression; was Chair of the Royal Society of Literature; former President of English PEN; Chair of Freud Museum; chaired 2017 Booker International Prize; Honorary Fellow of St Benet's Hall, Oxford and visiting professor in the Department of English at King's College London, and held a Wellcome Trust; has written for The New York Review of Books, The Guardian and The Observer, as well as making programmes and appearing on the BBC; was Director of Talks and Seminars at the Institute of Contemporary Arts (ICA) in London; was made a Chevalier of the Ordre des Arts et des Lettres and was appointed Officer of the Most Excellent Order of the British Empire (OBE) in the 2013 New Year Honours for services to literature. She became a Fellow of the Royal Society of Literature in 2015 and became the Chair of the Royal Society of Literature Council in 2016. Neal Ascherson (born 5 October 1932) journalist and writer; described by Radio Prague as "one of Britain's leading experts on central and eastern Europe".
Sources: en.wikipedia.org
=== Mechanism of elastic recoil === The characterization of disorder is consistent with an entropy-driven mechanism of elastic recoil. It is concluded that conformational disorder is a constitutive feature of elastin structure and function.
== Further reading == William F. Neuman and Margaret W. Neuman. (1958). The Chemical Dynamics of Bone Mineral. Chicago: The University of Chicago Press. ISBN 0-226-57512-8. Netter, Frank H. (1987). Musculoskeletal system: anatomy, physiology, and metabolic disorders. Summit, New Jersey: Ciba-Geigy Corporation ISBN 0-914168-88-6.
==== Inflammatory problems ==== High incidences of coexisting inflammatory disorders suggest a correlation between connective tissue disorders and the development of such aforementioned conditions. Inflammatory bowel diseases such as Crohn's disease, ulcerative colitis and celiac disease are more common in EDS patients when compared to control groups. Of note, patients who are already diagnosed with an inflammatory bowel disorder are not necessarily likely to develop symptoms of a connective tissue disorder, as the two have separate but not totally confounding etiologies. Eosinophilic esophagitis, an inflammatory condition characterized by allergic-type reactions to various foods and chemicals and extensive esophageal remodeling, is eight times more likely in patients with connective tissue disorders when compared to patients without.
Sources: en.wikipedia.org
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。
天然胸腺素α1主要从胸腺组织提取，也可在脾脏和淋巴结中检出。目前研究和临床使用的多为化学合成版本，不再依赖动物组织。
胸腺素组分5是牛胸腺提取物的粗组分，包含多种肽。胸腺素α1是其中一种被纯化和表征的单一肽，具有明确的28个氨基酸序列。
Its sequence corresponds to the amino-terminal portion of prothymosin alpha, a larger protein present in many cell types. The isolated 28-residue peptide is a fragment of that protein rather than a separately encoded molecule, and laboratory material is produced by synthesis.