If you have been reading about 合成肽 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.
Updated 2026-02-09. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Class | Synthetic peptide | 28 residues; not a small-molecule compound |
| Molecular mass | About 3,106 Da | Monoisotopic mass of the unmodified chain |
| N-terminal group | Acetylated serine | Present in both native and synthetic forms |
| Secondary structure | Disulfide-constrained loop | One bridge between two cysteine residues |
| Typical source | Solid-phase synthesis | Early isolates came from bovine thymus extracts |
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。
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。
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 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.
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.
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.
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.
== Clinical significance == Human HGF plasmid DNA therapy of cardiomyocytes is being examined as a potential treatment for coronary artery disease as well as treatment for the damage that occurs to the heart after myocardial infarction. As well as the well-characterised effects of HGF on epithelial cells, endothelial cells and haemopoietic progenitor cells, HGF also regulates the chemotaxis of T cells into heart tissue. Binding of HGF by c-Met, expressed on T cells, causes the upregulation of c-Met, CXCR3, and CCR4 which in turn imbues them with the ability to migrate into heart tissue. HGF also promotes angiogenesis in ischemia injury. HGF may further play a role as an indicator for prognosis of chronicity for Chikungunya virus induced arthralgia. High HGF levels correlate with high rates of recovery. Excessive local expression of HGF in the breasts has been implicated in macromastia. HGF is also importantly involved in normal mammary gland development. HGF has been implicated in a variety of cancers, including of the lungs, pancreas, thyroid, colon, and breast. Increased expression of HGF has been associated with the enhanced and scarless wound healing capabilities of fibroblast cells isolated from the oral mucosa tissue.
=== NAADP binding proteins === IP3 binds directly to its cognate IP3 receptor which is therefore a true ligand-gated ion channel. In contrast, NAADP does not appear to bind directly to TPCs but requires an intermediate unknown accessory protein(s). In sea urchin egg homogenate and T-cells, the binding protein(s) may be smaller than TPCs themselves, judging by photoaffinity labelling with [32P]azido-NAADP. Therefore, the NAADP receptor was believed to be a multi-protein complex on acidic vesicles. In spite of a decade of graft using conventional biochemical purification, these proteins remained elusive. Recently, two different NAADP-binding proteins have finally been identified that are essential for TPC activation: LSm12 and JPT2.
Agarose gel electrophoresis is the routine method for resolving DNA in the laboratory. Agarose gels have lower resolving power for DNA than acrylamide gels, but they have greater range of separation, and are therefore usually used for DNA fragments with lengths of 50–20,000 bp (base pairs), although resolution of over 6 Mb is possible with pulsed field gel electrophoresis (PFGE). It can also be used to separate large protein molecules, and it is the preferred matrix for the gel electrophoresis of particles with effective radii larger than 5-10 nm. The pore size of the gel affects the size of the DNA that can be sieved. The lower the concentration of the gel, the larger the pore size, and the larger the DNA that can be sieved. However low-concentration gels (0.1 - 0.2%) are fragile and therefore hard to handle, and the electrophoresis of large DNA molecules can take several days. The limit of resolution for standard agarose gel electrophoresis is around 750 kb. This limit can be overcome by PFGE, where alternating orthogonal electric fields are applied to the gel. The DNA fragments reorientate themselves when the applied field switches direction, but larger molecules of DNA take longer to realign themselves when the electric field is altered, while for smaller ones it is quicker, and the DNA can therefore be fractionated according to size. Agarose gels are cast in a mold, and when set, usually run horizontally submerged in a buffer solution.
=== Amphibians === Plethodontid salamanders and chameleons have evolved a harpoon-like tongue to catch insects. The Neotropical poison dart frog and the Mantella of Madagascar have independently developed similar mechanisms for obtaining alkaloids from a diet of mites and storing the toxic chemicals in skin glands. They have also independently evolved similar bright skin colors that warn predators of their toxicity (by the opposite of crypsis, namely aposematism). Caecilians are lissamphibians that secondarily lost their limbs, superficially resembling snakes and legless lizards. Oldest known tetrapods (semi-aquatic Ichthyostegalia) resembled giant salamanders (body plan, lifestyle), though they are considered to be only distantly related.
Somorjai (born 1935), 1998 Wolf Prize in Chemistry Georg Ernst Stahl (1659–1734), Important work on fermentation Wendell Meredith Stanley (1904–1971), 1946 Nobel Prize in Chemistry Jean Servais Stas (1813–1891), Belgian analytical chemist Branko Stanovnik (born 1938), chemist Hermann Staudinger (1881–1965), polymer chemist, 1953 Nobel Prize in Chemistry Harry Steenbock (1886–1967), American biochemist, worked on ultraviolet irradiation William Howard Stein (1911–1980), 1972 Nobel Prize in Chemistry Thomas A. Steitz (1940–2018), 2009 Nobel Prize in Chemistry Douglas Stephan, Frustrated Lewis Pairs Rose Stern (1869–1953), first British woman member of the Royal Institute of Chemistry Alfred Stock (1876–1946), German inorganic chemist, known for work in mercury poisoning Brian Stoltz (born 1970), award-winning American organic chemist. Fraser Stoddart (1942–2024), Scottish chemist, a pioneer in the field of the mechanical bond Molly Shoichet, award-winning Canadian biomedical engineer known for her work in tissue engineering. She is the only person to be a fellow of the three National Academies in Canada F. Gordon A. Stone (1925–2011), British inorganic chemist S. Donald Stookey (1915–2014), American glass and ceramic chemist Gilbert Stork (1921–2017), 1995/6 Wolf Prize in Chemistry Friedrich August Kekulé von Stradonitz (1829–1896), German organic chemist, principal founder of chemical structure Yellapragada Subbarow (1895-1948), Indian biochemist known for discovery of ATP and synthesis of many new ground breaking compounds James B.
Sources: en.wikipedia.org
A ligament is a type of fibrous connective tissue in the body that connects bones to other bones. It also connects flight feathers to bones, in dinosaurs and birds. All 30,000 species of amniotes (land animals with internal bones) have ligaments. It is also known as articular ligament, articular larua, fibrous ligament, or true ligament.
The same phenomenon may happen in conditions that lead to hemolysis, the destruction of red blood cells; in hemolysis, the blood serum is also visibly discolored, while in rhabdomyolysis it is normal. If kidney damage has occurred, microscopy of the urine also reveals urinary casts that appear pigmented and granular.
The declaration's first safeguard clause referred to protecting the civil and religious rights of non-Jews in Palestine. The clause had been drafted together with the second safeguard by Leo Amery in consultation with Lord Milner, with the intention to "go a reasonable distance to meeting the objectors, both Jewish and pro-Arab, without impairing the substance of the proposed declaration". Arabs constituted around 90% of the population of Palestine, but – as stated by Ronald Storrs, Britain's Military Governor of Jerusalem between 1917 and 1920 – they were "not so much [named but] lumped together under the negative and humiliating definition of 'Non-Jewish Communities'". Additionally, there was no reference to protecting the political rights of this group, as there was regarding Jews in other countries. This lack of interest was frequently contrasted against the commitment to the Jewish community, with various terms used over subsequent years to regard the two obligations as linked. A heated question was whether the status of both groups had "equal weight", which the British government and the Permanent Mandates Commission held to be the case in the 1930 Passfield white paper. Balfour stated in February 1919 that Palestine was considered an exceptional case in which, referring to the local population, "we deliberately and rightly decline to accept the principle of self-determination," although he considered that the policy provided self-determination to Jews. Avi Shlaim considers this the declaration's "greatest contradiction".
Metallothionein biosynthesis can also be induced by certain hormones, pharmaceuticals, alcohols, and other compounds. Metallothionein expression is upregulated during fetal development, particularly in liver tissue.
Sources: en.wikipedia.org
== Reactive Histiocytosis == Systemic Histiocytosis (SH) was originally recognized in closely related Bernese Mountain Dogs. SH is a generalized histiocytic proliferative disease with a marked tendency to involve skin, ocular and nasal mucosa, and peripheral lymph nodes. The disease predominately affects young to middle aged male dogs (2–8 years), although cases in females have been observed. SH has been observed in other breeds less commonly (e.g. Irish Wolfhounds, Basset Hounds and others). Clinical signs vary with the severity and extent of the disease and include anorexia, marked weight loss, stertorous respiration and conjunctivitis with marked chemosis. Multiple cutaneous nodules may be distributed over the entire body, but are especially prevalent in the scrotum, nasal apex, nasal planum and eyelids. Peripheral lymph nodes are often palpably enlarged. The disease course may be punctuated by remissions and relapses, which may occur spontaneously especially early in the disease course. In severe disease, lesions become persistent and do not respond to immunosuppressive doses of corticosteroids. Cutaneous histiocytosis (CH) is a histiocytic proliferative disorder that primarily involves skin and subcutis and does not extend beyond the local draining lymph nodes. CH occurs in a number of breeds. Evidence of spread beyond the skin would invoke the diagnosis of SH, a closely related disorder. Lymphadenopathy has not been emphasized in published reports, and has only been documented in a small number of our cases.
Fentanyl has started to be mixed into illicitly manufactured opioids and benzodiazepines. Fentanyl contamination in cocaine, methamphetamine, ketamine, MDMA, and other drugs is common. A kilogram of heroin laced with fentanyl may sell for more than US$100,000, but the fentanyl itself may be produced far more cheaply, for about US$6,000 per kilogram. While Mexico and China are the primary source countries for fentanyl and fentanyl-related substances trafficked directly into the United States, India is emerging as a source for finished fentanyl powder and fentanyl precursor chemicals. The United Kingdom illicit drug market is no longer reliant on China, as domestic fentanyl production is replacing imports. The intravenous dose causing 50% of opioid-naive experimental subjects to die (LD50) is "3 mg/kg in rats, 1 mg/kg in cats, 14 mg/kg in dogs, and 0.03 mg/kg in monkeys." The LD50 in mice has been given as 6.9 mg/kg by intravenous administration, 17.5 mg/kg intraperitoneally, 27.8 mg/kg by oral administration, The safety margin in rats is ~280. The LD50 in humans is unknown. In 2023, overdose deaths in the US and Canada reached record numbers. While overdoses involving fentanyl in the United States have decreased in 2024, the overall percentage of overdoses involving fentanyl has remained stable between 70% and 80% from 2021 to 2024. According to a 2023 report from the United Nations Office on Drugs and Crime (UNODC), the increased numbers of deaths are not related to an increased number of users but to the lethal effects of fentanyl itself.
==== Golf ==== The university's golf teams have also been notably successful. The men's team won a national championship in 1992 (NCAA Division I Men's Golf Championships), and has produced a number of successful professionals, most notably Jim Furyk. The women's team won national championships in 1996, 2000 and 2018 (NCAA Women's Golf Championship). The women's golf program has produced professionals Annika Sörenstam, Lorena Ochoa, and Erica Blasberg.
Sources: en.wikipedia.org
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.
The single bridge between two cysteine residues holds the chain in a folded loop that influences its shape and its behavior in solution. Loss of the bridge through reduction or oxidation shifts chromatographic retention and is tracked during stability work.
It is a defined 28-residue sequence derived from a larger precursor, whereas many other thymic preparations are mixtures of several polypeptides. Its acetylated amino terminus and single disulfide bridge distinguish it chemically from unrelated thymic extracts.
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.