This is a working overview of thymosin alpha-1, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-05-04 and is reviewed periodically as new material appears.
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.
Lyophilized thymosin alpha 1 is typically stored refrigerated at 2 to 8 degrees Celsius and kept away from light. Reconstituted solutions are less stable and are usually used promptly after preparation. Repeated freeze-thaw cycles are avoided because they can promote aggregation and loss of activity. The peptide adsorbs to some plastic and glass surfaces, so a carrier protein is often added to dilute working solutions. Manufacturer instructions and published protocols both govern handling.
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.
| 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 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.
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.
胸腺素α1对免疫系统的影响涉及多种细胞类型。研究表明，它可促进未成熟T细胞向成熟T细胞分化，并增强T细胞对抗原刺激的增殖反应。树突状细胞在Tα1存在下表达更高水平的共刺激分子，从而更有效地呈递抗原。此外，自然杀伤细胞的活性也观察到上升。这些效应并非直接杀伤病原体，而是调节宿主免疫应答的强度与方向。
在信号层面，Tα1可能通过Toll样受体等模式识别受体发挥作用。部分实验显示，它能激活髓样分化因子88依赖的通路，进而促进核因子κB进入细胞核。这导致白细胞介素2、干扰素γ和白细胞介素12等细胞因子的转录增加。这些细胞因子偏向辅助性T细胞1型应答，有助于细胞免疫。然而，具体受体和结合位点尚未完全确定，不同实验模型的结果存在差异。
To assist in a diagnosis, healthcare providers may also order a electrocardiogram (ECG or EKG), coronary calcium scan, stress test, cardiac magnetic resonance imaging (MRI), cardiac positron emission tomography (PET), invasive coronary angiography, and/or coronary CT angiography.
Erbium (for Ytterby, a village in Sweden) was discovered by Carl Gustaf Mosander in 1843. Mosander was working with a sample of what was thought to be the single metal oxide yttria, derived from the mineral gadolinite. He discovered that the sample contained at least two metal oxides in addition to pure yttria, which he named "erbia" and "terbia" after the village of Ytterby where the gadolinite had been found. Mosander was not certain of the purity of the oxides and later tests confirmed his uncertainty. Not only did the "yttria" contain yttrium, erbium, and terbium; in the ensuing years, chemists, geologists and spectroscopists discovered five additional elements: ytterbium, scandium, thulium, holmium, and gadolinium. Erbia and terbia, however, were confused at this time. Marc Delafontaine, a Swiss spectroscopist, mistakenly switched the names of the two elements in his work separating the oxides erbia and terbia. After 1860, terbia was renamed erbia and after 1877 what had been known as erbia was renamed terbia. Fairly pure Er2O3 was independently isolated in 1905 by Georges Urbain and Charles James. Reasonably pure erbium metal was not produced until 1934 when Wilhelm Klemm and Heinrich Bommer reduced the anhydrous chloride with potassium vapor.
Eastern Approaches – Fitzroy Maclean's memoir provides his personal experiences in the fledgling SAS in the Western Desert Campaign. Bravo Two Zero – Memoir about a failed SAS mission by Andy McNab. Bravo Two Zero – 1999 miniseries based on the book of the same name by Andy McNab. Red Notice – Novel by Andy McNab, part of his Tom Buckingham Series. SAS: Red Notice – 2021 film based on the book of the same name by Andy McNab. The One That Got Away – Memoir about the Bravo Two Zero mission by Chris Ryan. The One That Got Away – Film based on the book of the same name by Chris Ryan. The Feather Men – Novel by Sir Ranulph Fiennes, claimed by the author to be a partly non-fictional story involving the SAS. Killer Elite – Film based on The Feathermen, about a mercenary hired to kill SAS troopers (fictional story surrounding real events and people from SAS history). 6 Days – Film about the SAS involvement in the Iranian Embassy siege in 1980. Who Dares Wins – 1982 film, released in the United States as The Final Option. SAS: Rogue Heroes – 2016 book. Television shows about the SAS
Sources: en.wikipedia.org
gastrointestinal adverse effects (such as abdominal pain and nausea); dysgeusia (distorted sense of taste), in case of administration of vancomycin oral solution, but not in case of vancomycin capsules.
MMP-19 MMPs 11, 14, 15, 16, and 17 MMP-2 and MMP-9 All the other MMPs Analysis of the catalytic domains in isolation suggests that the catalytic domains evolved further once the major groups had differentiated, as is also indicated by the substrate specificities of the enzymes.
Typically, the base for lean is a strong prescription cold medicine, specifically cough syrup that contains both promethazine and codeine. Other preparations use codeine/guaifenasin, hydrocodone/chlorphenamine, hydrocodone/APAP, and hydrocodone/homatropine. Over-the-counter cold medicines that contain dextromethorphan (often paired with guaifenasin or acetaminophen) as the active ingredient have also been used, as they do not require acquiring a prescription. To create a drinkable mixture, the cough syrup is combined with soft drinks, especially fruit-flavored drinks such as Sprite, Mountain Dew, or Fanta, and is often served in foam cups. A hard candy, usually a Jolly Rancher, may be added to give the mixture a sweeter flavor. Masking the undesired taste may impair judgment of the potency, which is a factor in overdosing.
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.
The lyophilized powder is kept refrigerated at 2 to 8 degrees Celsius and protected from light. Reconstituted solutions should be used promptly. Freezing and thawing repeatedly is avoided.