prothymosin alpha comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-05-08. Numbers and descriptions here follow the published literature rather than marketing material.
Immune signaling studies link thymosin alpha 1 to Toll-like receptor pathways, particularly TLR2 and TLR9, on dendritic cells and other antigen-presenting cells. Activation of these receptors promotes maturation of T cells and increases natural killer cell activity. The peptide shifts cytokine output toward a T helper 1 profile, raising interferon gamma and interleukin 2 while modulating interleukin 10. Whether these effects translate into clinical benefit for any specific disease remains a subject of debate. Reported outcomes vary across trials and populations.
Thymosin alpha 1 is approved as a medicine in several countries, including Italy and China, for indications such as chronic hepatitis B and as an immune adjuvant. It is not approved by the United States Food and Drug Administration as a therapeutic product. In research settings the peptide appears in studies of sepsis, vaccine response, and oncology support, often with mixed or inconclusive results. The evidence base is uneven, and reviews note that many trials were small. Regulatory status therefore differs widely between jurisdictions.
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。
| Property | Value | Notes |
|---|---|---|
| Molecular mass | ≈3,108 Da | Synthetic 28-residue peptide |
| Amino acid count | 28 | N-terminal serine carries an acetyl group |
| Appearance | White to off-white powder | Lyophilized solid |
| Water solubility | Freely soluble | Dissolves in aqueous buffer |
| Common synonyms | Thymalfasin; Tα1 | Thymalfasin is the international nonproprietary name |
Stability depends on temperature, pH, and the number of freeze-thaw events the sample has experienced. Freeze-dried material is commonly held at -20 °C or colder, while reconstituted liquid is kept cold and used within a short window. Extreme pH and prolonged light exposure can promote deamidation, oxidation, or aggregation, particularly at asparagine and methionine positions. Adsorption to container walls can lower the measured concentration of a dilute solution even when the peptide molecules themselves remain intact.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, which separates the target peptide from truncated or chemically modified byproducts. Mass spectrometry confirms the expected molecular mass and can indicate acetylation state or sequence errors. Amino acid analysis and peptide mapping supply complementary sequence-level information, while endotoxin testing is relevant for preparations intended for cell or animal work. Purity figures reported by suppliers refer to the method used and are not directly comparable across laboratories unless conditions are stated.
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.
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.
Thymosin alpha-1 is a synthetic 28-amino-acid peptide whose sequence was first identified in extracts of bovine thymus tissue during the 1970s. The chain carries an acetyl group on its N-terminal serine. Its acidic residue content is high, which produces strong water solubility and an isoelectric point well below neutrality. Material supplied for laboratory and clinical use is manufactured by solid-phase peptide synthesis rather than purified from animal tissue. Different salt forms, such as the acetate, alter the counter-ion content without changing the peptide backbone.
In 1865 the German chemist Adolf von Baeyer began working on the synthesis of indigo. He described his first synthesis of indigo in 1878 (from isatin) and a second synthesis in 1880 (from 2-nitrobenzaldehyde). (It was not until 1883 that Baeyer finally determined the structure of indigo.) The synthesis of indigo remained impractical, so the search for alternative starting materials at Badische Anilin- und Soda-Fabrik (BASF) and Hoechst continued. In 1890, Dr Flimm of Darmstadt, Germany, discovered a simple method for synthesizing indigo with a derivative of acetanilide using caustic potash. This reaction produced a blue compound chemically identical to natural indigo that was identified by its reactions and absorption spectrum. This publication of independent dye synthesis experiments in scientific journals during this period demonstrates that the production of synthetic indigo was a widely pursued goal in industrial chemistry well before BASF's successful market launch. By 1897, BASF had developed an economically viable synthesizing process that replaced natural plant production. Earlier attempts to replace plant-based production were ineffective on an industrial scale. Johannes Pfleger and Karl Heumann eventually came up with industrial mass production synthesis. The synthesis of N-(2-carboxyphenyl)glycine from the easy to obtain aniline provided a new and economically attractive route. BASF developed a commercially feasible manufacturing process that was in use by 1897, at which time 19,000 tons of indigo were being produced from plant sources.
=== Resistance === Animals that accumulate TTX as a defense mechanism as well as their predators must evolve to be resistant to the effects of TTX. Mutations in the VGSC genes, especially the genes for Nav 1.4 (skeletal muscle VGSC, "TTX-s"), are found in many such animals. These mutations have independently arisen several times, even multiple times in different populations of the same species as seen in the garter snake. They consist of different amino acid substitutions in similar positions, a weak example of convergent evolution caused by how TTX binds to the unmutated VGSC. Another path to TTX resistance is toxin-binding proteins that hold onto TTX tightly enough to prevent it reaching the vulnerable VGSCs. Various proteins that bind TTX have been found in pufferfish, crabs, and gastropods. There are also proteins that bind saxitoxin (STX), a toxin with a similar mode of action.
In plants and most microorganisms, tyrosine is produced via prephenate, an intermediate on the shikimate pathway. Prephenate is oxidatively decarboxylated with retention of the hydroxyl group to give p-hydroxyphenylpyruvate, which is transaminated using glutamate as the nitrogen source to give tyrosine and α-ketoglutarate. Mammals synthesize tyrosine from the essential amino acid phenylalanine (Phe), which is derived from food. The conversion of Phe to Tyr is catalyzed by the enzyme phenylalanine hydroxylase, a monooxygenase. This enzyme catalyzes the reaction causing the addition of a hydroxyl group to the end of the 6-carbon aromatic ring of phenylalanine, such that it becomes tyrosine.
==== Justification for intervention ==== The US and UN gave public justifications for involvement in the conflict, the most prominent being the Iraqi violation of Kuwaiti territorial integrity. In addition, the US moved to support its ally Saudi Arabia, whose importance in the region, and as a key supplier of oil, made it of considerable geopolitical importance. Shortly after the Iraqi invasion, US defense secretary Dick Cheney made the first of several visits to Saudi Arabia where King Fahd requested US military assistance. During a speech in a special joint session of the US Congress given on 11 September 1990, Bush summed up the reasons with the following remarks: "Within three days, 120,000 Iraqi troops with 850 tanks had poured into Kuwait and moved south to threaten Saudi Arabia. It was then that I decided to act to check that aggression." The Pentagon stated that satellite photos showing a buildup of Iraqi forces along the border were the source of this information, but this was later alleged to be false. A reporter for the St. Petersburg Times acquired commercial Soviet satellite images which showed nothing but empty desert. Other justifications for foreign involvement included Iraq's history of human rights abuses under Saddam. Iraq was known to possess biological weapons and chemical weapons, which Saddam had used against Iranian troops during the Iran–Iraq War and his own country's Kurdish population in the Al-Anfal campaign. Iraq was known to have a nuclear weapons program; the report about it from January 1991 was partially declassified by the CIA in May 2001.
Native enteropeptidase and the isolated light chain have similar activity toward Gly-(Asp)4-Lys-NHNap, but the secluded light chain has distinctly decreased activity toward trypsinogen . An analogous selective defect in the recognition of trypsinogen can be produced in two-chain enteropeptidase by heating or by acetylation. This behavior implies that the catalytic center and one or more secondary substrate-binding sites are essential for optimal recognition of trypsinogen.
Sources: en.wikipedia.org
=== Glucagon === Glucagon is a hormone that rapidly counters the metabolic effects of insulin in the liver, causing glycogenolysis and release of glucose into the blood. It can raise the glucose by 30–100 mg/dL within minutes in any form of hypoglycemia caused by insulin excess (including all types of diabetic hypoglycemia). It comes in a glucagon emergency rescue kit which includes tiny vials containing 1 mg, which is a standard adult dose. The glucagon in the vial is a lyophilized pellet, which must be reconstituted with 1 mL of sterile water, included in the "kit". In the widely used Lilly Emergency Kit, the water is contained in a syringe with a large needle for intramuscular injection and must be injected into the vial with the pellet of glucagon before being injected. Glucagon works if given subcutaneously, but absorption and recovery are faster if it is injected deep into a muscle (usually the middle of the outside of the thigh). It has an even more rapid effect when given intravenously but this is rarely practicable. Side effects of glucagon can include nausea and headache, but these can also occur after severe hypoglycemia even when glucagon is not used. Risks of glucagon use are far lower than risks of severe hypoglycemia, and it can usually produce a faster recovery than calling for paramedics and waiting for them to start an intravenous line to give dextrose. If someone uses this kit, they should be seen in an emergency room, as glucagon depletes glycogen stores, and can lead to a deadly rebound hypoglycemia.
=== EC 1.1.98 With other, known, acceptors === EC 1.1.98.1: Now EC 1.1.9.1, alcohol dehydrogenase (azurin) EC 1.1.98.2: glucose-6-phosphate dehydrogenase (coenzyme-F420) EC 1.1.98.3: decaprenylphospho-β-D-ribofuranose 2-oxidase EC 1.1.98.3: decaprenylphospho-β-D-ribofuranose 2-dehydrogenase EC 1.1.98.4: F420H2:quinone oxidoreductase EC 1.1.98.5: secondary-alcohol dehydrogenase (coenzyme-F420) EC 1.1.98.6: ribonucleoside-triphosphate reductase (formate) EC 1.1.98.7: serine-type anaerobic sulfatase-maturating enzyme
Anxiety disorders Bobble-head doll syndrome – a sensation that the skull may fall off the cervical spine Clumsiness and motor delay Cognitive and memory decline Double or blurred vision Dysphagia – a sensation of choking Dyspnea Fatigue Lhermitte's sign Migraine Nausea Neck, shoulder, and jaw pain Occipital headaches Orthostatic intolerance Photophobia Syncope Tenderness at base of skull Tinnitus Tremors Palpitations Vertigo or dizziness Weakness of limbs Symptoms are frequently worsened by a Valsalva maneuver or by being upright for long periods of time. Being upright is problematic because gravity allows increased interaction between the brain stem and the top of the spinal column, increasing symptoms. Lying in the supine position can bring short-term relief. Lying supine eliminates the downward gravitational pull, reducing symptoms to some degree. Lying with the feet somewhat higher and head lower can be helpful in symptom reduction.
Despite this, the use of urine myoglobin measurement is not supported by evidence as it lacks specificity and the research studying its utility is of poor quality. Elevated concentrations of the enzyme lactate dehydrogenase (LDH) may be detected. Other markers of muscle damage, such as aldolase, troponin, carbonic anhydrase type 3 and fatty acid-binding protein (FABP), are mainly used in chronic muscle diseases. The transaminases, enzymes abundant in both liver and muscle tissue, are also usually increased; this can lead to the condition being confused with acute liver injury, at least in the early stages. The incidence of actual acute liver injury is 25% in people with non-traumatic rhabdomyolysis; the mechanism for this is uncertain. High potassium levels tend to be a feature of severe rhabdomyolysis. Electrocardiography (ECG) may show whether the elevated potassium levels are affecting the conduction system of the heart, as suggested by the presence of T wave changes or broadening of the QRS complex. Low calcium levels may be present in the initial stage due to binding of free calcium to damaged muscle cells. As detectable levels of myoglobinemia and myoglobinuria occur, blood tests and urine tests may show elevated levels of myoglobin. For example, a urine test strip may reveal a positive result for "blood", even though no red blood cells can be identified on microscopy of the urine; this occurs because the reagent on the test strip reacts with myoglobin.
Sources: en.wikipedia.org
It is a chain of 28 amino acids, with an acetyl group attached to the first serine residue. The synthetic version replicates this sequence. Its molecular mass is about 3,108 daltons.
It is usually described as an immunomodulatory peptide rather than a classic hormone. It acts on immune cells through receptor pathways. No single endocrine organ target defines its function.
Several countries, including Italy and China, allow it for specific indications. The FDA has not approved it as a drug in the United States. Availability depends on local regulation.
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。