Everything below concerns Thymosin fraction 5. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-01-04. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
Thymosin alpha-1 is a synthetic peptide of 28 amino acid residues that corresponds to a naturally occurring fragment first isolated from thymus tissue. Its chain is acetylated at the amino terminus, a modification that shields the peptide from rapid cleavage by aminopeptidases. The molecule carries a net negative charge at physiological pH and dissolves freely in water. Researchers classify it as an immune-modulating agent rather than a classical hormone, because it acts on several cell types of both the innate and the adaptive immune system.
The peptide was identified during work in the 1970s on thymosin fraction 5, a partially purified extract of calf thymus. Investigators separated that mixture and characterized individual components, one of which they named thymosin alpha-1. The same compound later received the international nonproprietary name thymalfasin. Commercial material is produced by solid-phase peptide synthesis rather than by extraction, so synthetic and natural forms share an identical sequence. Naming conventions vary across the literature, and readers should distinguish the alpha-1 peptide from other thymosins that have unrelated sequences and functions.
| Property | Value | Notes |
|---|---|---|
| 化学分类 | 线性肽 | 由28个氨基酸组成 |
| 分子量 | 约3108 Da | 合成版本一致 |
| 外观 | 白色至类白色粉末 | 冻干品 |
| 溶解度 | 易溶于水 | 微溶于有机溶剂 |
| 储存温度 | -20°C（冻干） | 溶解后2-8°C |
Thymosin alpha 1 is a short peptide of 28 amino acid residues that derives from the amino terminal region of a larger precursor protein known as prothymosin alpha. The peptide carries an acetyl group on its first residue and contains no disulfide bonds or carbohydrate chains. Its sequence is highly conserved across mammalian species, which is one reason laboratories treat it as a molecule with a defined and reproducible structure rather than a variable tissue extract. The name follows an early naming convention for thymus-derived fractions and does not imply that the peptide acts as a hormone in the classical endocrine sense.
Biologically, the peptide is studied mainly in the context of immune cell development and regulation. It is produced in the thymus and in several other tissues, and it appears to influence the maturation and activity of T cells and other immune populations. Laboratory work describes effects on cytokine production, on the balance between T cell subsets, and on the function of dendritic cells. Much of this evidence comes from cell culture and animal models, so the extent to which the same pathways operate in humans remains an open question.
Clinical interest has centered on chronic viral hepatitis, on immune restoration in various conditions, and on use as an adjuvant intended to improve responses to vaccines. Trials have reported mixed results, and regulatory status differs sharply between countries; in some places it is a prescription product, while elsewhere it is sold without an approved therapeutic indication. Because published studies vary widely in design, population, and endpoints, comparisons across them are difficult and no single conclusion covers the whole literature.
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.
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.
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.
Penicillium expansum is a psychrophilic blue mold that is common throughout the world in soil. It causes Blue Mold of apples, one of the most prevalent and economically damaging post-harvest diseases of apples. Though primarily known as a disease of apples, this plant pathogen can infect a wide range of hosts, including pears, strawberries, tomatoes, corn, and rice. Penicillium expansum produces the carcinogenic metabolite patulin, a neurotoxin that is harmful when consumed. Patulin is produced by the fungus as a virulence factor as it infects the host. Patulin levels in foods are regulated by the governments of many developed countries. Patulin is a particular health concern for young children, who are often heavy consumers of apple products. The fungus can also produce the mycotoxin citrinin.
DNA microarray A high-throughput technology used to measure expression levels of mRNA transcripts or to detect certain changes in nucleotide sequence. It consists of an array of thousands of microscopic spots of DNA oligonucleotides, called features, each containing picomoles of a specific DNA sequence. This can be a short section of a gene or any other DNA element, and is used as a probe to hybridize a cDNA, cRNA, or genomic DNA sample (called a target) under high-stringency conditions. Probe-target hybridization is usually detected and quantified by fluorescence-based detection of fluorophore-labeled targets.
=== Anti-mold === In certain cases, a nystatin derivative has been used to prevent the spread of mold on objects such as works of art. For example, it was applied to wood panel paintings damaged as a result of the Arno River Flood of 1966 in Florence, Italy.
Sources: en.wikipedia.org
== Education == Greenspan studied at New York University College of Arts & Science and graduated in 1974. His graduate studies were on the SV40 large T-Ag oncogene of the SV40 DNA virus. He received his master's degree in 1978, and Doctoral degree in 1981 from New York University Medical School.
=== Greek philosophy === In Ancient Greece, Aristotle remarked on the importance of semen: "For Aristotle, semen is the residue derived from nourishment, that is of blood, that has been highly concocted to the optimum temperature and substance. This can only be emitted by the male as only the male, by nature of his very being, has the requisite heat to concoct blood into semen." According to Aristotle, there is a direct connection between food and semen: "Sperms are the excretion of our food, or to put it more clearly, as the most perfect component of our food." The connection between food and physical growth, on the one hand, and semen, on the other, allows Aristotle to warn against "engag[ing] in sexual activity at too early an age ... [since] this will affect the growth of their bodies. Nourishment that would otherwise make the body grow is diverted to the production of semen.
=== q-RASAR === QSAR has been merged with the similarity-based read-across technique to develop a new field of q-RASAR. The DTC Laboratory at Jadavpur University has developed this hybrid method and the details are available at their laboratory page. Recently, the q-RASAR framework has been improved by its integration with the ARKA descriptors in QSAR.
Sources: en.wikipedia.org
The threading of the lasso tail is trapped either by disulfide bonds between ring and tail cysteine residues (class I lasso peptides), by steric effects due to bulky residues on the tail (class II lasso peptides), or both (class III lasso peptides). The compact structure makes lasso peptides frequently resistant to proteases or thermal unfolding.
The tertiary alcohol tert-amyl alcohol (TAA), also known as 2-methylbutan-2-ol (2M2B), has a history of use as a hypnotic and anesthetic, as do other tertiary alcohols such as methylpentynol, ethchlorvynol, and chloralodol. Unlike primary alcohols like ethanol, these tertiary alcohols cannot be oxidized into aldehyde or carboxylic acid metabolites, which are often toxic, and for this reason, these compounds are safer in comparison. Other relatives of ethanol with similar effects include chloral hydrate, paraldehyde, and many volatile and inhalational anesthetics (e.g., chloroform, diethyl ether, and isoflurane).
== Side effects == Possible adverse effects include temporary bone pain, joint pains (arthralgias), dizziness, elevated blood pressure (hypertension) and elevated uric acid levels (hyperuricemia). There was also an increased risk of thrombosis (blood clots) in patients who have risk factors for thrombosis who are taking luspatercept.
Each exists in the form of a hydrogen phosphate anion ([HPO4]2−), dissociating to contribute 2H+ overall Each liberates an oxygen atom when it binds to an adenosine diphosphate (ADP) molecule, contributing 2 O overall Charges are balanced by the difference between ADP and ATP. In the cellular environment, all three hydroxyl groups of ADP dissociate into −O− and H+, giving ADP3−, and this ion tends to exist in an ionic bond with Mg2+, giving ADPMg−. ATP behaves identically except that it has four hydroxyl groups, giving ATPMg3−. When these differences along with the true charges on the two phosphate groups are considered together, the net charges of −4 on each side are balanced. In high-oxygen (aerobic) conditions, eukaryotic cells can continue from glycolysis to metabolise the pyruvate through the citric acid cycle or the electron transport chain to produce significantly more ATP. Importantly, under low-oxygen (anaerobic) conditions, glycolysis is the only biochemical pathway in eukaryotes that can generate ATP, and, for many anaerobic respiring organisms the most important producer of ATP. Therefore, many organisms have evolved fermentation pathways to recycle NAD+ to continue glycolysis to produce ATP for survival. These pathways include ethanol fermentation and lactic acid fermentation.
Sources: en.wikipedia.org
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。
天然胸腺素α1主要从胸腺组织提取，也可在脾脏和淋巴结中检出。目前研究和临床使用的多为化学合成版本，不再依赖动物组织。
胸腺素组分5是牛胸腺提取物的粗组分，包含多种肽。胸腺素α1是其中一种被纯化和表征的单一肽，具有明确的28个氨基酸序列。
It is a 28-residue synthetic peptide studied as an immune-modulating agent and approved as a drug in some countries. The sequence matches a naturally occurring fragment isolated from thymus tissue. It is not a hormone in the endocrine sense.