The short version of 胸腺素α1 fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-11-26 and is reviewed periodically as new material appears.
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.
The peptide is generated in cells by cleavage of prothymosin alpha, a larger acidic protein encoded by the PTMA gene. Prothymosin alpha is expressed in many tissues, not only in the thymus, and its functions include nuclear roles in chromatin-related processes. The 28-residue fragment corresponds to the N-terminal portion of that precursor. How the cleavage occurs and how the fragment's concentration is regulated remain open questions; circulating amounts are small and difficult to measure reliably with routine assays.
Overall evidence quality varies considerably. A large share of published reports come from single centers, rely on surrogate immunological markers, or lack adequate control groups. Systematic reviews have highlighted this heterogeneity as a barrier to pooling results. Open questions include which patients, if any, might benefit, what treatment duration is appropriate, and whether any effect is independent of standard care. The peptide is often described as an immune modulator rather than a therapy for one disease, which complicates confirmatory trial design.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Acetylated peptide | N-terminal acetyl group blocks aminopeptidase attack |
| Residue count | 28 amino acids | Matches the N-terminus of prothymosin alpha |
| Molecular mass | About 3,108 Da | Value for the free, unmodified peptide |
| Isoelectric point | Approximately 4.2 | Acidic; net negative charge at neutral pH |
| Encoding gene | PTMA | Human gene for the precursor protein |
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。
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.
== Adverse effects == Adverse effects of clorazepate include tolerance, dependence, withdrawal reactions, cognitive impairment, confusion, anterograde amnesia, falls in the elderly, ataxia, hangover effects, and drowsiness. It is unclear whether cognitive deficits resulting from the long-term use of benzodiazepines return to normal or persist indefinitely after withdrawal from benzodiazepines. Benzodiazepines are also known to cause or worsen depression. Paradoxical effects including excitement and paradoxical worsening of seizures can sometimes result from the use of benzodiazepines. Children, the elderly, individuals with a history of alcohol use disorder or a history of aggressive behavior and anger are at greater risk of developing paradoxical reactions to benzodiazepines. In September 2020, the U.S. Food and Drug Administration (FDA) required the boxed warning be updated for all benzodiazepine medicines to describe the risks of non-medical use, addiction, physical dependence, and withdrawal reactions consistently across all the medicines in the class.
The 3' poly(A) tail is a long sequence of adenine nucleotides (often several hundred) added to the 3' end of the pre-mRNA. This tail promotes export from the nucleus and translation, and protects the mRNA from degradation.
Sulfur can also be removed from fuels before burning, preventing formation of SO2 when the fuel is burnt. The Claus process is used in refineries to produce sulfur as a byproduct. The Stretford process has also been used to remove sulfur from fuel. Redox processes using iron oxides can also be used, for example, Lo-Cat or Sulferox. Fuel additives such as calcium additives and magnesium carboxylate may be used in marine engines to lower the emission of sulfur dioxide gases into the atmosphere.
Similarly, focal adhesions occur between the undersurface of the greater omentum and the cephalad aspect of the transverse mesocolon. These can be accessed after dividing the peritoneal fold that links the greater omentum and transverse colon. Adhesions here must be divided to separate the greater omentum off the transverse mesocolon, thus allowing access to the lesser sac proper. The fetal sigmoid colon mesentery can be visualised during routine ultrasound examination from the 12th week of pregnancy.
Green mambas (western, eastern, and Jameson's) are all highly venomous snakes that can be highly aggressive and unpredictable in disposition. They can suddenly go from a state of relative calm to an extremely agitated and dangerous state. All three species have a tendency to strike repeatedly with little provocation, although they are generally much less aggressive than their larger cousin, the black mamba. All three species of green mamba are highly arboreal, alert, extremely quick, and agile. Although the potency of their venom is similar to the more venomous cobra species, mamba venom is much more rapid-acting and the dendrotoxins contained in mamba venom is generally more devastating in nature to the central nervous system, causing more severe neurotoxicity in more rapid fashion. The western green mamba (Dendroaspis viridis) is highly venomous and aggressive with a LD50 of 0.7 mg/kg SC and the average venom yield per bite is approximately 100 mg. The mortality rate of untreated bites is unknown but is thought to be very high (>80%). The eastern green mamba (Dendroaspis angusticeps) has an average venom yield per bite of 80 mg according to Engelmann and Obst (1981). The subcutaneous LD50 for this species ranges from 0.40 mg/kg to 3.05 mg/kg depending on different toxicology studies, authority figures and estimates. The mortality rate of untreated bites is unknown but is thought to be very high (70–75%). Generally the calmest and most shy of the green mamba species, the Eastern green will still strike repeatedly if cornered or agitated.
Sources: en.wikipedia.org
The three substrates of this enzyme are asparagusic acid, reduced nicotinamide adenine dinucleotide (NADH), and a proton. Its products are 3-mercapto-2-mercaptomethylpropanoic acid and oxidised NAD+. This enzyme belongs to the family of oxidoreductases, specifically those acting on a sulfur group of donors with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is 3-mercapto-2-mercaptomethylpropanoate:NAD+ oxidoreductase. Other names in common use include asparagusate dehydrogenase, asparagusic dehydrogenase, asparagusate reductase (NADH2), and NADH2:asparagusate oxidoreductase.
== External links == "Richardson Laboratory website". "MolProbity structure validation website". "Jane and David Richardson Papers, Duke University Medical Center Archives". "Jane S. Richardson Oral History Interview, Duke University Medical Center Archives".
== Contraindications == Pseudoephedrine is contraindicated in patients with diabetes mellitus, cardiovascular disease, severe or uncontrolled hypertension, severe coronary artery disease, prostatic hypertrophy, hyperthyroidism, closed-angle glaucoma, or by pregnant women. The safety and effectiveness of nasal decongestant use in children is unclear.
Polycondensation involves the formation of polymers through condensation reactions between different species, creating condensation polymers. With automated synthesis, General electric manufactured an approach for melt-polymerizations of BPA and diphenyl carbonate (DPC), using sodium hydroxide (NaOH) as the catalyst. Once the results were analyzed, it was shown that, by using an automated method of polymerization, the effect of varying the catalyst amount became more distinct and improved the reproducibility for the reaction. Furthermore, it demonstrated an increase within the homogeneity of the polymers in the microreactors.
Sources: en.wikipedia.org
=== Role in Infectious Disease Pathogenesis === Certain pathogens, such as Enterotoxigenic Escherichia coli (ETEC), elevate cGMP to evade host immune defenses and establish infection. ETEC's heat-stable toxin induces significant cGMP production within intestinal epithelial cells, and this cGMP is often secreted into the extracellular space, where it serves as a signaling molecule. Extracellular cGMP, in turn, triggers the release of IL-33 release which modulate inflammation and impact the immune system's ability to mount effective responses, dampening both innate and adaptive immunity.
== Treatment == For people with the FOLR1 mutation, even when the systemic deficiency is corrected by folate (the oxidized form - folic acid), the cerebral deficiency remains, and must be treated with folinic acid. Folinic acid is a metabolically active form of folate that can be easily introduced into the folate cycle. A typical dose that is administered to children is 0.5–1 mg/kg daily, but the dose can be increased depending on the severity of symptoms and the age of the child. Over time, the treatment with folinic acid has shown to reduce a variety of symptoms of CFD. The treatment of folinic acid can lead to improvements in walking, speech, interpersonal skills and reduction in seizures. Success depends on early initiation of treatment. Starting the folinic acid treatment before the age of six is more advantageous for the child with CFD. If the treatment is started after the age of six, its results are not as effective. Treatment requires taking folinic acid for lengthy periods. Fewer than 20 people with the FOLR1 defect have been described in the medical literature. Folinic acid (5-formyl-THF, 5-fTHF) also appears useful for some other forms of CFD. Pharmacologic doses of folinic acid has also led to reversal of some symptoms in children diagnosed with cerebral folate deficiency and testing positive for autoantibodies to folate receptor alpha. It also appears useful in DHFR deficiency and AADC deficiency. 5-MTHF (5-methyl-THF) is also available as a drug (levomefolic acid). It is "thought to be the most efficient way to restore CSF 5-MTHF concentrations".
During atrial systole, blood flows from the atria to the ventricles down the pressure gradient. Chordae tendineae are relaxed because the atrioventricular (AV) valves are forced open. When the ventricles of the heart contract in ventricular systole, the increased blood pressures in both chambers push the AV valves to close simultaneously, preventing the backflow of blood into the atria. Since the blood pressure in the atria is much lower than that in the ventricles, the flaps attempt to evert to the low pressure regions. The chordae tendineae prevent this prolapse by becoming tense, which pulls on the flaps, holding them in a closed position.
Abbreviations are used very frequently in medicine, despite being widely discouraged by the Institute of Safe Medicine Practices and other organizations concerned about patient safety. Abbreviations are especially discouraged when healthcare providers are communicating with patients and when there is a possibility of confusion between similar abbreviations. Some facilities maintain a list of acceptable abbreviations. Abbreviations are sometimes specific to a facility, which means that newer staff may be unfamiliar with them; this becomes a potential source of preventable medical errors. The Joint Commission and other organizations maintain lists of certain medical abbreviations that should be avoided to prevent mistakes, according to best practices (and in some cases regulatory requirements); these are flagged in the list of abbreviations used in medical prescriptions.
Strychnine was commonly used as an athletic performance enhancer and stimulant in the late 19th century and early 20th century. The best-known incident of this usage was during the 1904 Olympics marathon, when track-and-field athlete Thomas Hicks was administered a concoction of egg whites and brandy that contained strychnine by his assistants in an attempt to boost his stamina; Hicks did not know that it contained strychnine. Maximilian Theodor Buch proposed that strychnine was a cure for alcoholism. Although strychnine has no known addictive properties, in The Invisible Man (1897), H. G. Wells imagined the protagonist, Griffin, to be a strychnine addict:
Sources: en.wikipedia.org
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.
The precursor, prothymosin alpha, is encoded by the PTMA gene in humans. The 28-residue peptide corresponds to the N-terminal segment released from that larger protein.
It is produced as a fragment of prothymosin alpha and is present in many tissues. Circulating concentrations are low, which makes routine measurement difficult.
Trials differ in patient population, dose schedule, background treatment, and the endpoints used to judge success. Many are small and single-center, so random variation can dominate the reported effects.