Everything below concerns 胸腺素α1. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-05-17. Numbers and descriptions here follow the published literature rather than marketing material.
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。
Lyophilized material is typically treated as a hygroscopic solid that should be brought to room temperature before the container is opened, which limits condensation on the powder. Reconstitution is commonly done with sterile water or a buffered diluent, and gentle mixing is preferred over vigorous agitation to reduce foaming and surface adsorption. Because peptides can bind to plastic and glass, diluents containing a small amount of carrier protein are sometimes used in laboratory work. Working solutions are generally aliquoted and prepared fresh rather than subjected to repeated freezing and thawing.
Stability depends on temperature, pH, and the number of freeze-thaw events the sample has experienced. Freeze-dried material is commonly held at -20 °C or colder, while reconstituted liquid is kept cold and used within a short window. Extreme pH and prolonged light exposure can promote deamidation, oxidation, or aggregation, particularly at asparagine and methionine positions. Adsorption to container walls can lower the measured concentration of a dilute solution even when the peptide molecules themselves remain intact.
| 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 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 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.
== Drug interactions == Repaglinide is a major substrate of CYP3A4 and should not be administered concomitantly with gemfibrozil, clarithromycin or azole antifungals such as itraconazole or ketoconazole. Administration of both repaglinide and one or more of these drugs results in an increase in plasma concentration of repaglinide and may lead to hypoglycemia. Co-administration of repaglinide and clopidogrel (a CYP2C8 inhibitor) may lead to a significant decrease in blood glucose levels due to a drug-drug interaction. In fact, using these drugs together for even one day can cause repaglinide levels to increase over 5-fold...and may lead to significant hypoglycemia. Repaglinide should not be combined with sulfonylurea, because they have the same mechanism of action.
In July 2017, Matthew Bryza stated at the conference in Warsaw: "President Putin was preparing to invade Georgia. Those preparations went on for years, and when I would ring the alarm bell I would often be told that I should focus more on managing President Saakashvili [...] At one point, it was no longer possible to calm down Saakashvili, Russian troops poured into Georgia, Saakashvili ended up getting blamed by the international narrative for having launched the war. I'll go to my grave thinking it was absolutely wrong based on the intelligence I was reading, it was a provocation by Russia." In 2018, former Polish ambassador to Russia Katarzyna Pełczyńska-Nałęcz stated during a discussion that "the whole situation of this war was such that it really was very difficult to explain that the Russians actually attacked.
== New National Hospital Project == The New National Hospital project (Icelandic: Nýr Landspítali, NLSH) is a large-scale public infrastructure project aimed at replacing the existing facilities of Landspítali. The hospital currently operates across multiple buildings in several locations in the greater Reykjavík area, many of which are said to longer meet modern healthcare requirements.
Sources: en.wikipedia.org
== Bibliography == Grigoroff, Stamen (1905). "Etude sur le lait fermenté comestible : le 'Kissélo-mléko' de Bulgarie". Revue Médicale de la Suisse Romande (in French). Genève: Libraires-Éditeurs. Librairie de L'Université. OCLC 717162535. Balows A, Truper HG, Dworkin M, Harder W, Schleifer KH (1992). "70". The Prokaryotes: A Handbook on the Biology of Bacteria (2nd ed.). New York: Springer-Verlag. p. 1547. ISBN 978-3-540-97258-7. OCLC 23767548.
United Nations Security Council Resolution 283 was passed in June 1970 calling for all UN member states to close, or refrain from establishing, diplomatic or consular offices in South West Africa. The resolution also recommended disinvestment, boycotts, and voluntary sanctions of that territory as long as it remained under South African rule. In light of these developments, the Security Council sought the advisory opinion of the ICJ on the "legal consequences for states of the continued presence of South Africa in Namibia". There was initial opposition to this course of action from SWAPO and the OAU, because their delegates feared another inconclusive ruling like the one in 1966 would strengthen South Africa's case for annexation. Nevertheless, the prevailing opinion at the Security Council was that since the composition of judges had been changed since 1966, a ruling in favour of the nationalist movement was more likely. At the UN's request, SWAPO was permitted to lobby informally at the court and was even offered an observer presence in the courtroom itself. On 21 June 1971, the ICJ reversed its earlier decision not to rule on the legality of South Africa's mandate, and expressed the opinion that any continued perpetuation of said mandate was illegal. Furthermore, the court found that Pretoria was under obligation to withdraw its administration immediately and that if it failed to do so, UN member states would be compelled to refrain from any political or business dealings which might imply recognition of the South African government's presence there.
Sivasankar and his research team have found that the mechanism behind the puzzling phenomenon is due to long-lived, force-induced hydrogen bonds. Using data from previous experiments, the team used molecular dynamics to discover that two rod-shaped cadherins in an X-dimer formed catch bonds when pulled and in the presence of calcium ions. The calcium ions keep the cadherins rigid, while pulling brings the proteins closer together, allowing for hydrogen bonds to form. The mechanism behind catch bonds helps to explain the biophysics behind cell-cell adhesion. According to the researchers, "Robust cadherin adhesion is essential for maintaining the integrity of tissue such as the skin, blood vessels, cartilage and muscle that are exposed to continuous mechanical assault." The above catch bonds are formed between adhesion receptors and ligands, and among structural molecules and motor proteins, which bear force or generate force in their physiological function. An interesting recent development is the discoveries of catch bonds formed between signaling receptors and their ligands. These include bonds between T cell antigen receptors (TCR) or pre-TCR and peptide presented by major histocompatibility complex (pMHC) molecules, Fc gamma receptor and IgG Fc, and notch receptor and ligands. The presence of catch bonds in the interactions of these signaling (rather than adhesion) receptors have been suggested to be indicative of a possible role of these receptors as mechanoreceptors.
Sources: en.wikipedia.org
Aspartate transaminase, as with all transaminases, operates via dual substrate recognition; that is, it is able to recognize and selectively bind two amino acids (Asp and Glu) with different side-chains. In either case, the transaminase reaction consists of two similar half-reactions that constitute what is referred to as a ping-pong mechanism. In the first half-reaction, amino acid 1 (e.g., L-Asp) reacts with the enzyme-PLP complex to generate ketoacid 1 (oxaloacetate) and the modified enzyme-PMP. In the second half-reaction, ketoacid 2 (α-ketoglutarate) reacts with enzyme-PMP to produce amino acid 2 (L-Glu), regenerating the original enzyme-PLP in the process. Formation of a racemic product (D-Glu) is very rare. The specific steps for the half-reaction of enzyme-PLP + aspartate ⇌ {\displaystyle \rightleftharpoons } enzyme-PMP + oxaloacetate are as follows (see figure); the other half-reaction (not shown) proceeds in the reverse manner, with α-ketoglutarate as the substrate.
The functional form of single-stranded RNA molecules, just like proteins, frequently requires a specific spatial tertiary structure. The scaffold for this structure is provided by secondary structural elements that are hydrogen bonds within the molecule. This leads to several recognizable "domains" of secondary structure like hairpin loops, bulges, and internal loops. In order to create, i.e., design, RNA for any given secondary structure, two or three bases would not be enough, but four bases are enough. This is likely why nature has "chosen" a four base alphabet: fewer than four would not allow the creation of all structures, while more than four bases are not necessary to do so. Since RNA is charged, metal ions such as Mg2+ are needed to stabilise many secondary and tertiary structures. The naturally occurring enantiomer of RNA is D-RNA composed of D-ribonucleotides. All chirality centers are located in the D-ribose. By the use of L-ribose or rather L-ribonucleotides, L-RNA can be synthesized. L-RNA is much more stable against degradation by RNase. Like other structured biopolymers such as proteins, one can define topology of a folded RNA molecule. This is often done based on arrangement of intra-chain contacts within a folded RNA, termed as circuit topology.
Some groups of people have specialized transfusion requirements. Fetuses, very low-birth-weight infants, and immunocompromised people are at risk for developing severe infection with cytomegalovirus (CMV)―an opportunistic pathogen for which approximately 50% of blood donors test positive―and may be transfused with CMV-negative blood to prevent infection. Those who are at risk of developing graft-versus-host disease, such as bone marrow transplant recipients, receive blood that has been irradiated to inactivate the T lymphocytes that are responsible for this reaction. People who have had serious allergic reactions to blood transfusions in the past may be transfused with blood that has been "washed" to remove plasma. The history of the patient is also examined to see if they have previously identified antibodies and any other serological anomalies. A direct antiglobulin test (Coombs test) is also performed as part of the antibody investigation. Donor blood is generally screened for transfusion-transmitted infections such as HIV. As of 2018, the World Health Organization reported that nearly 100% of blood donations in high- and upper-middle-income countries underwent infectious disease screening, but the figures for lower-middle-income and low-income countries were 82% and 80.3% respectively.
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。
Cold storage slows the chemical degradation reactions that occur in solution. Lyophilized powder is more stable than reconstituted liquid and tolerates longer storage periods. Repeated temperature cycling should still be avoided because it can drive aggregation and loss of material.