If you have been reading about 胸腺素α1 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 2025-09-14. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Thymosin alpha 1 is a short peptide first isolated from bovine thymus tissue in the early 1970s during fractionation work aimed at identifying factors that influence T cell development. It belongs to a family of acidic thymic peptides, and the original preparations contained several components that were later separated by chromatography. The compound is now produced synthetically rather than extracted from tissue, which removes batch variability tied to animal sourcing. Researchers describe it as an immunomodulatory peptide because laboratory studies show effects on several cell types of the innate and adaptive immune systems.
The molecule consists of 28 amino acid residues with an acetyl group attached to the N-terminal serine. Its sequence is acidic overall, with several glutamic and aspartic acid residues distributed along the chain and no cysteine, so disulfide bridges do not form. The peptide carries a net negative charge at physiological pH. Because the N-terminus is blocked, the intact molecule resists degradation by many aminopeptidases, which contributes to its stability in biological fluids.
| 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 |
Thymosin alpha 1 was identified in 1977 as a component of thymosin fraction 5, a heterogeneous preparation used in early studies of thymic function. Investigators purified the active material and determined its amino acid sequence, which enabled chemical synthesis. Work in the following decades concentrated on T-cell maturation and immune reconstitution in animals and small human cohorts. Early preparations varied in composition, so results from that period are difficult to compare with studies using defined synthetic peptide.
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Findings across trials are mixed; some report changes in selected immune markers, while others find no clear clinical benefit. Many studies are small and define outcomes differently, which limits comparison. Regulatory approval is confined to a few countries, and the compound is not an approved drug in the United States or most of Europe.
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。
=== Helmut Kohl === In October 1982 the SPD–FDP coalition fell apart when the FDP joined forces with the CDU/CSU to elect CDU Chairman Helmut Kohl as Chancellor in a constructive vote of no confidence. Following national elections in March 1983, Kohl emerged in firm control of both the government and the CDU. The CDU/CSU fell just short of an absolute majority, due to the entry into the Bundestag of the Greens, who received 5.6% of the vote. In January 1987 the Kohl–Genscher government was returned to office, but the FDP and the Greens gained at the expense of the larger parties. Kohl's CDU and its Bavarian sister party, the CSU, slipped from 48.8% of the vote in 1983 to 44.3%. The SPD fell to 37%; long-time SPD Chairman Brandt subsequently resigned in April 1987 and was succeeded by Hans-Jochen Vogel. The FDP's share rose from 7% to 9.1%, its best showing since 1980. The Greens' share rose to 8.3% from their 1983 share of 5.6%.
=== Oxanorbornadiene cycloaddition === The oxanorbornadiene cycloaddition is a 1,3-dipolar cycloaddition followed by a retro-Diels Alder reaction to generate a triazole-linked conjugate with the elimination of a furan molecule. Preliminary work has established its usefulness in peptide labeling experiments, and it has also been used in the generation of SPECT imaging compounds. More recently, the use of an oxanorbornadiene was described in a catalyst-free room temperature "iClick" reaction, in which a model amino acid is linked to the metal moiety, in a novel approach to bioorthogonal reactions.
=== Menu === The menu, which features hot specialty subs, salads, and other seasonal items, takes inspiration from the firehouse with names like Hook & Ladder, Engineer, and Firehouse Hero. The subs are prepared with meats and cheeses, on toasted sub rolls, and served "Fully Involved" with vegetables and condiments. Chris and Robin remain in charge of the menu, and work alongside their director of product development Jay Miller, who joined the company in 2017.
Sources: en.wikipedia.org
A salvage pathway is a pathway in which a biological product is produced from intermediates in the degradative pathway of its own or a similar substance. The term often refers to nucleotide salvage in particular, in which nucleotides (purine and pyrimidine) are synthesized from intermediates in their degradative pathway. Nucleotide salvage pathways are used to recover bases and nucleosides that are formed during degradation of RNA and DNA. This is important in some organs because some tissues cannot undergo de novo synthesis. The salvaged products can then be converted back into nucleotides. Salvage pathways are targets for drug development, one family being called antifolates. A number of other biologically-important substances, like methionine and nicotinate, have their own salvage pathways to recycle parts of the molecule.
Even greater inconsistency and confusion is associated with various "Non-GMO" or "GMO-free" labeling schemes in food marketing, where even products such as water or salt, which do not contain any organic substances and genetic material (and thus cannot be genetically modified by definition), are being labeled to create an impression of being "more healthy".
The press over the litigation and public concern over the claims of A2 Corporation led the New Zealand Food Safety Authority and the Ministry of Health and the Food Standards Australia New Zealand to issue statements confirming the safety of conventional milk. A2 Corporation was able to obtain agreements with enough dairy farmers to launch A1 protein-free milk under its a2 and a2 MILK brands in New Zealand at the end of April 2003. In the middle of 2003, both founders of the company died. In July, Paterson was found dead in his hotel room during a business trip at the age of 50, and a month later Dr Corran McLachlan died of cancer at the age of 59. In New Zealand it is illegal to make health claims about a food product without providing scientific evidence and registering the food as a medicine, and in November 2003 the New Zealand Commerce Commission advised that A2 Corporation Ltd and its licensed producers of A1 protein-free milk had agreed to amend the health claims in their promotional material following a warning from the commission. By end of 2003 the weakened A2 Corporation had withdrawn the litigation against Fonterra and negotiations had resumed. The company, which had been in a tenuous financial situation since beginning trading in May, went into administration in October and was liquidated in November, owing farmers and processors tens of thousands of dollars. A NZ$1.27 million federal government grant awarded to the company in August as part of the Regional Partnerships Program was also cancelled.
Sources: en.wikipedia.org
Sodium-based action potentials usually last for under one millisecond, but calcium-based action potentials may last for 100 milliseconds or longer. In some types of neurons, slow calcium spikes provide the driving force for a long burst of rapidly emitted sodium spikes. In cardiac muscle cells, on the other hand, an initial fast sodium spike provides a "primer" to provoke the rapid onset of a calcium spike, which then produces muscle contraction.
Eukaryotic translation termination factor 1 (eRF1), also referred to as TB3-1 or SUP45L1, is a protein that is encoded by the ERF1 gene. In Eukaryotes, eRF1 is an essential protein involved in stop codon recognition in translation, termination of translation, and nonsense mediated mRNA decay via the SURF complex.
== Suspended fighters == The list below is based on fighters suspended either by (1) United States Anti-Doping Agency (USADA) or World Anti-Doping Agency (WADA) for violation of taking prohibited substances or non-analytical incidents, (2) by local commissions on misconduct during the fights or at event venues, or (3) by the UFC for reasons also stated below.
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.
Thymosin fraction 5 is a mixture of many peptides obtained from thymus tissue, while thymosin alpha 1 is a single defined 28-residue molecule. The two names appear together in older literature because the purified peptide was first obtained from that mixture.