If you have been reading about acetylated peptide 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 2026-06-29. Numbers and descriptions here follow the published literature rather than marketing material.
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.
The peptide was described in the 1970s as a component of thymic extracts, and early research focused on restoring immune function in immunodeficiency states. A synthetic version entered clinical development in the 1980s and is approved as a drug in several countries for conditions such as chronic hepatitis B and certain immunodeficiencies. Approval status varies widely by jurisdiction, and in the United States it is not an approved therapeutic. Regulatory and clinical positions differ, so statements about efficacy should be tied to specific indications and studies.
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 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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic peptide, 28 residues | N-terminal fragment of prothymosin alpha |
| Molecular mass | About 3108 Da | Acetylated form |
| Isoelectric point | Near 4.2 | Acidic peptide |
| Appearance | White to off-white lyophilized powder | Common supplied form |
| Typical storage | -20 °C or below, dry | Solution stability is lower |
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.
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。
== List of anorectics == Numerous pharmaceutical compounds are marketed as appetite suppressants. The following drugs are listed as "centrally-acting antiobesity preparations" in the Anatomical Therapeutic Chemical Classification System:
==== Effects in preclinical studies ==== Trazodone shows antidepressant- and anxiolytic-like effects in animals. However, it shows differences from certain other antidepressants, like the tricyclic antidepressants, in animals. For example, it does not reverse the behavioral effects of the monoamine depleting agent reserpine and does not potentiate the effects of amphetamine or levodopa. Similarly to antipsychotics, trazodone reduces spontaneous motor activity, spontaneous and elicited aggressive behavior, and exploratory behavior, among other effects. In addition, trazodone diminishes amphetamine-induced locomotor hyperactivity, although it does not inhibit apomorphine- or amphetamine-induced stereotypy. On the other hand, unlike antipsychotics, trazodone does not produce catalepsy, although it can do so at sufficiently high doses. Activation of the serotonin 5-HT2A receptor enhances striatal dopaminergic neurotransmission, while stimulation of the serotonin 5-HT2C receptor inhibits striatal dopaminergic neurotransmission. Trazodone is both a serotonin 5-HT2A and 5-HT2C receptor antagonist, but has about 15-fold greater potency as an antagonist of the 5-HT2A receptor relative to the 5-HT2C receptor. In addition, at higher doses, trazodone acts as a dopamine D2 receptor antagonist in animals. As a result of the preceding actions, trazodone may inhibit striatal dopaminergic neurotransmission. This may underlie exacerbation of parkinsonism seen in marmosets and in human case reports.
=== Dietary sources === Asparagine is not essential for humans, which means that it can be synthesized from central metabolic pathway intermediates and is not required in the diet. Asparagine is found in:
== Bibliography == Lui, G.; Bruenger, F.W.; Barrios, A. M.; Miller, S.C. (1995). "Synthesis of 2-Alkyl-3-Hydroxy-4-Pyridinone-Ribonucleosides, Potential Oral Iron Chelators". Nucleosides and Nucleotides. 14: 1901–1904. Barrios, A.M. and Lippard, S.J. (2000). "Interaction of Urea with a Hydroxide-Bridged Dinuclear Nickel Center: An Alternative Model for the Mechanism of Urease". J. Am. Chem. Soc.. 122(38): 9172–9177. Barrios, A.M. and Craik, C.S. (2002). "Scanning the Prime-Site Substrate Specificity of Proteolytic Enzymes: A Novel Assay Based on Ligand-Enhanced Lanthanide Ion Fluorescence". Bioorg. Med. Chem. Lett.. 12: 3619–3623. Stanford, S.M.; Panchal, R.G.; Walker, L.M.; Falk, M.D.; Mitra, S.; Damle, S.S.; Ruble, D.; Kaltcheva, T.; Zhang, S.; Zhang, Z.-Y.; Bavari, S.; Barrios, A.M.; Bottini, N. (2012). "High-Throughput Screen Using a Single-Cell Tyrosine Phosphatase Assay Reveals Biologically Active CD45 Inhibitors". Proc. Natl. Acad. Sci.. 109(35): 13972–13977. Barrios, A. and Mitra, S. (July 2, 2015). "Coumarin-based amino acids for use in enzyme activity and substrate specificity assays". United States Patent and Trademark Office. Bottini, N.; Stanford. S.; Barrios, A.; Mitra, S. (March 19, 2013). "Method for monitoring intracellular tyrosine phosphatase activity". United States Patent and Trademark Office. Debnath, A.; Parsonage, D.; Andrade, R.; He, C.; Cobo, E.; Hirata, K.; Chen, S.; Garcia-Rivera, G.; Orozco, E.; Martinez, M.; Gunatilleke, S.; Barrios, A.M.; Arkin, M.; Poole, L.; McKerrow, J.; Reed, S. (2012).
== Mechanism of activation == Opioid receptors are a type of G protein–coupled receptor (GPCR). These receptors are distributed throughout the central nervous system and within the peripheral tissue of neural and non-neural origin. They are also located in high concentrations in the periaqueductal grey, locus coeruleus, and the rostral ventromedial medulla. The receptors consist of an extracellular amino acid N-terminus, seven trans-membrane helical loops, three extracellular loops, three intracellular loops, and an intracellular carboxyl C-terminus. Three GPCR extracellular loops provide a compartment where signalling molecules can attach to generate a response. Heterotrimeric G protein contain three different sub-units, which include an alpha (α) subunit, a beta (β) subunit, and a gamma (γ) sub-unit. The gamma and beta sub-units are permanently bound together, producing a single Gβγ sub-unit. Heterotrimeric G proteins act as 'molecular switches', which play a key role in signal transduction, because they relay information from activated receptors to appropriate effector proteins. All G protein α sub-units contain palmitate, which is a 16-carbon saturated fatty acid, that is attached near the N-terminus through a labile, reversible thioester linkage to a cysteine amino acid. It is this palmitoylation that allows the G protein to interact with membrane phospholipids due to the hydrophobic nature of the alpha sub-units. The gamma sub-unit is also lipid modified and can attach to the plasma membrane as well.
Sources: en.wikipedia.org
=== Negative factors === Diabetes, cardiovascular disease, urgent initiation, inadequate dialysis (Kt/V <1.2), infections. COVID-19 increased mortality in 2020 but rates declined by 2022. In low-resource settings, median survival may be ~1.5 years due to access barriers.
In the mid-1980s to 1990s, Singaporeans could also use the locally based videotext service Singapore Teleview to communicate with one another. The phrase Intelligent Island arose in the 1990s in reference to the island nation's early adaptive relationship with the internet. In 2016, there were an estimated 4.7 million internet users in Singapore, representing 82.5% of the population. The Singapore government does not engage in widespread censoring of the internet, but it maintains a list of one hundred websites—mostly pornographic—that it blocks from home internet access as a "symbolic statement of the Singaporean community's stand on harmful and undesirable content on the Internet". Singapore has the world's highest smartphone penetration rates, in surveys by Deloitte and the Google Consumer Barometer—at 89% and 85% of the population respectively in 2014. The overall mobile phone penetration rate is at 148 mobile phone subscribers per 100 people.
Baeckeoffe, a potato stew from Alsace Beef bourguignon, a French dish of beef stewed in red burgundy wine Bigos, a traditional stew in Polish cuisine Birria, a traditional stew from Mexico Bo kho (Vietnamese: bò kho), a beef stew in rich seasonings, served with bread, noodle or plain rice from Vietnam Bollito misto, consisting of beef, veal, and pork simmered in an aromatic vegetable broth from Italy Booyah, an American meat stew Bosnian pot, a stew with beef or lamb which is a national dish in Bosnia and Herzegovina Bouillabaisse, a fish stew from Provence Brongkos, a spicy Javanese meat with beans stew from Indonesia, made of Pangium edule, coconut milk, and various spices Brunswick stew, from Virginia and the Carolinas Burgoo, a Kentuckian stew Brudet, fish stew from Dalmatia regions, known in Greece as bourdeto Caldeirada, a fish stew from Portugal Carbonade flamande (stoofvlees), a traditional Belgian beef and onion stew made with Belgian beer Cawl, a Welsh stew Chakapuli, a Georgian stew made with lamb chops, coriander and tarragon leaves, and white wine Chanakhi, a Georgian lamb stew with tomatoes, aubergines, potatoes, greens, and garlic Charquicán, a Chilean dish Chicken mull, whole chicken and seasonings Chicken paprikash, chicken stew with paprika Chili con carne, a meat and chili pepper stew originating in Texas Chilorio, a pork stew from Sinaloa, Mexico Cincinnati chili, developed by Macedonian immigrants from Greece immigrants in the Cincinnati area Cholent, a slow-cooked Jewish dish Chorba (also spelt "shorba"), a stew like soup dish found in various North African, Middle Eastern, Central Asian, South Asian, and European cuisines Cochinita pibil, an orange color pork stew from Yucatán Peninsula, Mexico Cocido, a traditional Spanish and Portuguese strew with many variants (madrileño, montañés, à portuguesa, etc.) Cotriade, a fish stew from Brittany Cream stew, a yōshoku Japanese white stew Crow stew, a sour cream-based stew made with crow meat, popular in the United States during the Great Depression Daal, the Indian legume stew that has many varieties, a staple food throughout Asia Dalma, a traditional dish of Odisha, India; contains pulses with vegetables Daube, a French stew made with cubed beef braised in wine, vegetables, garlic, and herbs Dinuguan, pork blood stew from the Philippines Eintopf, ('one pot') the German word for a stew: many different regional specialty recipes for Eintopf are known in Germany. For example, the Kassel area has a type called Lumben un Fleeh in the local dialect (Standard German: Lumpen und Flöhe – 'rags and fleas'), which is quite similar to Irish stew. There are thicker German stews such as Hasenpfeffer or Labskaus; these would not usually be considered an Eintopf, though the technical difference is minor (longer cooking times and fewer vegetables) Estofadong baboy, pork stew from the Philippines Ewedu, vegetable stew from Nigeria Fabada asturiana, an Asturian bean and meat stew Feijoada, Brazilian or Portuguese bean stew Fårikål, traditional Norwegian stew with lamb or mutton and white cabbage Főzelék, a thick Hungarian vegetable dish Gaisburger Marsch, a German dish of stewed beef served with Spätzle and potatoes Gheimeh, an Iranian stew with cubed lamb and yellow split peas Ghormeh sabzi, an Iranian stew with green herbs, dried limes, beans, and sheep meat Goulash, a Hungarian meat stew with paprika Gumbo, a Louisiana creole dish Hachee, a Dutch type of stew with wine or vinegar Haleem, an Indian-Pakistani lentil and beef stew Hasenpfeffer, a sour, marinated rabbit stew from Germany Hayashi rice, a Japanese dish of beef, onions and mushrooms in red wine and demi-glace sauce, served with rice Irish stew, made with lamb or mutton, potato, onion, and parsley Ishtu, a curry in Kerala, India made from chicken or mutton, potato, and coconut milk Istrian stew or yota, or jota, a dish popular in Croatian and Slovenian Istra and NE Italy I-tal stew, a Rastafarian vegan dish of mostly Caribbean root vegetables and spices Jjigae, a diverse range of Korean stews Kaldereta, a goat meat stew from the Philippines Kalops, a traditional Swedish beef stew, with onions and carrots, served with potatoes and pickled beets Kare-kare, stewed beef or oxtail and vegetables in peanut sauce from the Philippines Karelian hot pot, from the region of Karelia in eastern Finland Kharcho is a traditional Georgian soup containing beef, rice, cherry plum purée, and chopped walnuts Khash, a traditional Armenian/Azerbaijani dish of pig's or cow's feet Khoresht, a variety of Persian stews, often prepared with saffron Kokkinisto, Greek stew with red meat, in a tomato passata with shallots, cinnamon, and other spices Kuurdak, a type of stew from Central Asia Kuzhambu, (also called Pulusu or Saaru, depending on region) a range of stews from southern India based on tamarind broth and vegetables, meat or fish Lobscouse, a Norwegian stew with beef, potato, onion, and carrot Lancashire hotpot, an English stew Lecsó, a summertime favourite in Hungary, vegetable stew with bell pepper and tomato as main ingredients Linseneintopf ("lentil stew") Lobby, a stew from Staffordshire, England Locro, a stew (mainly in the Andes region) Machanka, a Belarus and Ukraine pork stew Matelote, a French fish stew made with freshwater fish, fish stock, and wine Mechado, a Philippine beef stew Moppelkotze Moqueca, a Brazilian stew with fish (or shrimp, crab, or other seafood) as its main ingredient Mućkalica, a Serbian stew Nihari, an Indian meat stew, usually made with goat, chicken, lamb and less commonly beef. It is made overnight and served for breakfast. Nikujaga, a Japanese beef and potato stew Oil down, national dish of Grenada, made of breadfruit, salted meat, chicken, dumplings, callaloo, coconut milk, and spices Olla podrida, a Spanish red bean stew Pašticada, a Croatian stew from the region of Dalmatia Peperonata, an Italian stew made with peppers Pepposo, a Tuscan beef stew Pescado blanco, a white fish stew from Pátzcuaro, Michoacán, Mexico Pichelsteiner a traditional German stew Pörkölt, a Hungarian meat stew resembling goulash, flavoured with paprika Potjiekos, a South African stew Pot-au-feu, a simple French beef stew Pozole, a Mexican stew or soup Puchero, a stew from Andalusia, Spain, also common in South America and the Philippines Ratatouille, a French vegetable stew Rendang, an Indonesian spicy beef stew Ragoût, a French stew Sāmbār, a lentil-based spiced vegetable stew, cooked with pigeon pea and tamarind broth in South Indian cuisine Sancocho, a stew from the Caribbean Scouse, a stew commonly eaten by sailors throughout Northern Europe, popular in seaports such as Liverpool Semur, a typical Indonesian stew with beef or chicken, potatoes, carrots, various spices, and kecap manis (sweet soy sauce) Stufato, an Italian stew Steckrübeneintopf (based on rutabaga) Slumgullion, a watery stew of meat and vegetables Tagine, a Moroccan stew, named after the conical pot in which it is traditionally cooked or served Tocană, a Romanian stew prepared with tomato, garlic, and sweet paprika Tharid, a traditional Arab stew of bread in broth Wat, an Ethiopian and Eritrean stew Waterzooi, a Belgian stew Yahni, a Greek (γιαχνί), Turkish, and Persian stew
== Function == Alpha cells function in the maintenance of blood glucose levels. Alpha cells are stimulated to produce glucagon in response to hypoglycemia, epinephrine, amino acids, other hormones, and neurotransmitters.
Sources: en.wikipedia.org
It corresponds to a fragment of the larger protein prothymosin alpha, which is present in many tissues. The isolated 28-amino-acid peptide was originally obtained from thymus preparations, and the pharmaceutical product is synthesized rather than extracted. The term therefore describes both a natural fragment and a manufactured drug substance.
Thymosin alpha-1 is a single defined 28-residue peptide, while the broader family includes unrelated peptides such as thymosin beta-4. The shared name reflects historical isolation from thymus tissue rather than a common structure. Confusion between the two is common in older literature.
No single pathway fully accounts for its reported effects. Several studies describe interaction with innate immune receptors and downstream cytokine changes, but the complete picture is not settled. Open questions remain about which effects occur at physiological concentrations.
It corresponds to the first 28 amino acids of thymosin beta-4, a larger protein found in many tissues. The fragment is acetylated at its N-terminus and is produced synthetically for research and pharmaceutical use. Synthetic and natural forms share the same sequence.