prothymosin alpha raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-11-20. Anything still debated is marked as such rather than presented as settled.
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。
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。
Several names appear in the literature for this peptide, including thymalfasin and the abbreviation T-alpha-1. Naming conventions differ among research articles, regulatory documents, and supplier catalogs, which complicates literature searches. Both synthetic and recombinant production routes yield a peptide with the same 28-residue sequence as the thymic isolate. Because the thymosin label also covers unrelated peptides, sources should be compared by sequence rather than by name alone.
The peptide occurs naturally in thymic tissue and has been detected in serum and other biological fluids. Reported concentrations are low, and reliable measurement generally requires immunoassay or mass spectrometry with an enrichment step. It is released from a larger precursor, prothymosin alpha, by proteolytic cleavage, although the enzymes involved are not fully characterized. Whether circulating levels reflect thymic output specifically remains an open question.
Thymosin alpha 1 is a 28-amino-acid peptide first isolated from thymosin fraction 5, a bovine thymic extract. Its sequence begins with an acetylated serine residue and carries a high proportion of acidic residues, so the molecule has a net negative charge near neutral pH. Despite the shared name, it is unrelated in sequence to the thymosin beta family. Synthetic material prepared by solid-phase peptide synthesis is identical in sequence to the natural peptide.
| 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 beta-4 is a separate 43-residue peptide that binds actin and participates in cell migration; it shares no sequence similarity with thymosin alpha-1 despite the common family name. Other preparative materials, such as thymosin fraction 5 and thymopoietin, contain distinct mixtures or peptides. The shared thymosin label reflects the tissue of origin used in early purification, not a common structural core. Treating these molecules as interchangeable is a frequent source of confusion in laboratory reports and in popular summaries alike.
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.
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.
The peptide lacks cysteine, methionine, and tryptophan, so disulfide scrambling and sulfur oxidation are not major degradation routes. Instead, aspartate residues can undergo isomerization or cyclization to succinimide intermediates, generating isoaspartate variants. Hydrolysis of peptide bonds also occurs slowly in solution. These changes may reduce biological activity even when the main peak remains detectable. Stability studies therefore track both potency and the appearance of related substances.
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.
The lyophilized peptide is generally stable for extended periods when kept cold and dry. Once dissolved, aqueous solutions are less stable; hydrolysis, oxidation, and aggregation can degrade the material. Storage at -20 °C or lower slows these processes. Repeated freeze-thaw cycles are best avoided because they can promote aggregation. The exact shelf life depends on formulation, pH, and concentration, so stability studies are typically performed for each specific product.
Quality control for thymosin alpha-1 focuses on identity, purity, and potency. Identity is confirmed by mass spectrometry and amino acid analysis, while purity is assessed by chromatography with limits on related substances and residual solvents. Potency assays may use cell-based immune readouts, but these are not standardized across laboratories. Regulatory status differs by jurisdiction; no product is approved in the United States for clinical use, whereas some other countries register injectable forms for specific indications.
Quantifying thymosin alpha-1 in a sample usually relies on reverse-phase high-performance liquid chromatography. The peptide lacks strong chromophores, so detection often occurs at 214 nm, where the peptide backbone absorbs. Mass spectrometry provides confirmatory identification and can detect sequence variants or truncations. Immunoassays have been used in biological matrices, but they may cross-react with related fragments. For purity assessment, chromatographic peak area gives the main component percentage, while mass accuracy verifies molecular identity.
=== Political system === Marxism–Leninism involves the creation of a one-party state led by a communist party, as a means to develop socialism and then communism. The communist party is the supreme political institution of the state. Marxism–Leninism asserts that the people's interests are fully represented through the communist party and other state institutions. In the words of historians Silvio Pons and Robert Service, elections are "generally not competitive, with voters having no choice or only a strictly limited choice". Generally, when alternative candidates have been allowed to stand for election, they have not been allowed to promote very different political views. In communist states, elections are generally held for all positions at all levels of government. In most states, this has taken the form of directly electing representatives, although in some states such as People's Republic of China, the Republic of Cuba and the Socialist Federal Republic of Yugoslavia, this also included indirect elections, such as deputies being elected by deputies as the next lower level of government.
=== Neuron survival === Binding interaction between NGF and the TrkA receptor facilitates receptor dimerization and tyrosine residue phosphorylation of the cytoplasmic tail by adjacent Trk receptors. Trk receptor phosphorylation sites operate as Shc adaptor protein docking sites, which undergo phosphorylation by the TrkA receptor Once the cytoplasmic adaptor protein (Shc) is phosphorylated by the receptor cytoplasmic tail, cell survival is initiated through several intracellular pathways. One major pathway leads to the activation of the serine/threonine kinase, Akt. This pathway begins with the Trk receptor complex-recruitment of a second adaptor protein called growth factor-receptor bound protein-2 (Grb2) along with a docking protein called Grb2-associated Binder-1 (GAB1). Subsequently, phosphatidylinositol-3 kinase (PI3K) is activated, resulting in Akt kinase activation. Study results have shown that blocking PI3K or Akt activity results in death of sympathetic neurons in culture, regardless of NGF presence. However, if either kinase is constitutively active, neurons survive even without NGF. A second pathway contributing to cell survival occurs through activation of the mitogen-activated protein kinase (MAPK) kinase. In this pathway, recruitment of a guanine nucleotide exchange factor by the adaptor and docking proteins leads to activation of a membrane-associated G-protein known as Ras. The guanine nucleotide exchange factor mediates Ras activation through the GDP-GTP exchange process.
== Adverse effects == The most common effects when taking dapoxetine are nausea, dizziness, dry mouth, headache, diarrhea, and insomnia. Discontinuation rates due to adverse effects and costs are very high, as demonstrated in a study in Asia which showed that cumulative discontinuation rates within one year are as high as 87%. Unlike other SSRIs used to treat depression, which have been associated with high incidences of sexual dysfunction, dapoxetine is associated with low rates of sexual dysfunction. Taken as needed, dapoxetine has very mild adverse effects of decreased libido (<1%) and erectile dysfunction (<4%).
=== 1964 === January 12: the Arab-dominated government of the Zanzibar Sultanate is overthrown by John Okello, establishing the new people's republic. The new regime orders a massacre against minorities, resulting in the deaths of hundred to thousand Arabs and South Asians in Zanzibar. January 27: France recognizes the People's Republic of China. The Republic of China severs diplomatic relations with France on February 10. March 31–April 1: A military-led coup d'état overthrows president João Goulart in Brazil. Goulart's proposals, such as land reform and bigger control of the state in the economy, were seen as communist. April 20: U.S. President Lyndon Johnson in New York, and Soviet First Secretary Nikita Khrushchev in Moscow, announce simultaneously plans to cut back production of materials for making nuclear weapons. May 27: Jawaharlal Nehru dies. The Colombian conflict begins. July 4: The Rhodesian Bush War begins when African nationalist / Marxist insurgents rebel against colonial rule in Rhodesia (modern-day Zimbabwe). Nyasaland (renamed Malawi upon independence) becomes independent from the UK. August 4: U.S. President Lyndon B. Johnson claims that North Vietnamese naval vessels had fired on two American destroyers in the Gulf of Tonkin. Although there was a first attack, it was later shown that American vessels had entered North Vietnamese territory first, and that the claim of second attack had been unfounded. The Gulf of Tonkin incident leads to the open involvement of the United States in the Vietnam War, after the Gulf of Tonkin Resolution.
Sources: en.wikipedia.org
marked insulin resistance (diabetes mellitus, metabolic syndrome) androgen excess (acromegaly, Cushing's disease, polycystic ovary syndrome) Addison's disease and hypothyroidism rare syndromes including Alström syndrome, Prader–Willi syndrome, Donohue syndrome, pinealoma, lipoatrophic diabetes, pituitary basophilism, pineal hyperplasia, ovarian hyperthecosis, stromal luteoma and ovarian dermoid cysts This form usually has a gradual onset and often occurs in people who are also obese.
=== Contestants === 1st - Sinai Vespie, Pastry Chef from Mishawaka, Indiana 2nd - Renee Loranger, Pastry Chef from Waveland, Mississippi 3rd - Aaron Clouse, Pastry Chef from Columbus, Ohio 4th - Michelle Lee, Sous Chef from Monterey, California 5th - Michael Gaddy, Pastry Chef from Dade City, Florida 6th - Brian Bosch, Event Designer from Santa Ana, California 7th - Tamara Brown, from Los Angeles, California 8th - Holly Braddock, Pastry Chef from Myrtle Beach, South Carolina 9th - Nerwan Khalife, Pastry Chef from Bronx, New York 10th - Edward Cunningham, Railroad Heavy Equipment Operator from Chicago, Illinois
== Career == Marks began his career in the late 1950s at the National Hospital for Neurology and Neurosurgery, focusing on detecting low blood sugar and researching pancreatic and glucose-management hormones. Notably, he simplified the testing for low blood glucose using glucose oxidase, a method that foreshadowed modern diabetes diagnostics including colour-changing glucose strips. Collaborating with South African medical researcher Ellis Samols, Marks introduced insulin radioimmunoassay into the UK, transforming insulin level measurement. The method had earlier been developed in the United States. Marks moved to Surrey in 1962, working as a consultant chemical pathologist in Epsom. He co-authored the textbook Hypoglycaemia in 1965, and later became a professor of biochemistry at the University of Surrey in 1970. Marks established a laboratory for insulin testing and founded a master's course in clinical pathology. His laboratory was among the first to offer insulin assays for testing across National Health Service (NHS) hospitals in the United Kingdom. His research extended to monitoring drug levels in the blood and investigating hormones like melatonin and insulin-like growth factors. Marks also studied intestinal hormones and helped designate the gastric inhibitory polypeptide (GIP) as an obesity hormone. He also coined the term "muesli belt malnutrition", referring to parents feeding their children what is considered extremely healthy foods, but, in the process depriving them of essential fats.
Disability and even deaths from excessive use of these products have been claimed. The U.S. Food and Drug Administration (FDA) states that zinc damages nerve receptors in the nose, causing anosmia. Reports of anosmia were also observed in the 1930s when zinc preparations were used in a failed attempt to prevent polio infections. On June 16, 2009, the FDA ordered removal of zinc-based intranasal cold products from store shelves. The FDA said the loss of smell can be life-threatening because people with impaired smell cannot detect leaking gas or smoke, and cannot tell if food has spoiled before they eat it. Recent research suggests that the topical antimicrobial zinc pyrithione is a potent heat shock response inducer that may impair genomic integrity with induction of PARP-dependent energy crisis in cultured human keratinocytes and melanocytes.
== Further reading == Buzuev, Vladimir; Gorodnov, Vladimir (1987). What Is Marxism–Leninism?. Moscow: Progress Publishers. "Marxism–Leninism". Encyclopedia of Marxism. Marxists Internet Archive. Retrieved 31 December 2020. Kuusinen, Otto Will (1963). Fundamentals of Marxism–Leninism. Translated by Dutt, Clemens (2nd rev. ed.). Moscow: Foreign Languages Publishing House. OCLC 1091006. OL 5975949M. Kuusinen, Otto Will (2022). Fundamentals of Marxism–Leninism. Translated by Dutt, Clemens. United States: Marx Engels Lenin Press. ISBN 979-8-8114-4663-6. Sheptulin, Alexander. Marxist-Leninist Philosophy. Moscow: Progress Publishers. OL 2170371W. Stalin, Joseph (1924). "The Foundations of Leninism". Works. Vol. 6. Moscow: Foreign Languages Publishing House. pp. 71–196. Spirkin, Alexander (1990). Fundamentals of Philosophy. Translated by Syrovatkin, Sergei. Moscow: Progress Publishers. ISBN 978-5-0100-2582-3.
Sources: en.wikipedia.org
=== General fertility assessment === Comparison of an individual's AMH level with respect to average levels is useful in fertility assessment, as it provides a guide to ovarian reserve. Because one's AMH level cannot be altered by any external factors, it helps identify whether a woman needs to consider either egg freezing or trying for a pregnancy sooner rather than later if their long-term future fertility is poor. A higher level of anti-Müllerian hormone when tested in women in the general population has been found to have a positive correlation with natural fertility in women aged 30–44 aiming to conceive spontaneously, even after adjusting for age. However, this correlation was not found in a comparable study of younger women (aged 20 to 30 years).
== External links == Investigational New Drug (IND) Application Process Center for Drug Evaluation and Research, Food and Drug Administration. ICH Guidance for Industry, E6 Good Clinical Practice: Consolidated Guidance. BROKEN LINK Troetel, W.M.: Achieving a Successful US IND Filing (1) The Regulatory Affairs Journal. 6: 22–28, January 1995. Troetel, W.M.: Achieving a Successful US IND Filing (2) The Regulatory Affairs Journal. 6: 104–108, February 1995. Henninger, Daniel (2002). "Drug Lag". In David R. Henderson (ed.). Concise Encyclopedia of Economics (1st ed.). Library of Economics and Liberty. Archived from the original on 2020-12-04. Retrieved 2013-08-31. OCLC 317650570, 50016270, 163149563 IND Forms and Instructions from the US Food and Drug Administration
== See also == Metal carbonyl cluster Metal carbon dioxide complex Metal phosphine complex – Chemical compounds containing phosphorus and metalsPages displaying short descriptions of redirect targets Alkaline earth octacarbonyl complex
Carvedilol is both a non-selective β-adrenergic receptor antagonist (β1, β2) and an α-adrenergic receptor antagonist (α1). The S(–) enantiomer accounts for the beta-blocking activity whereas the S(–) and R(+) enantiomers have alpha-blocking activity. The affinity (Ki) of carvedilol for the β-adrenergic receptors is 0.32 nM for the human β1-adrenergic receptor and 0.13 to 0.40 nM for the β2-adrenergic receptor. Using rat proteins, carvedilol has shown affinity for a variety of targets including the β1-adrenergic receptor, β2-adrenergic receptor, α1-adrenergic receptor, α2-adrenergic receptor, 5-HT1A receptor, 5-HT2 receptor, H1 receptor, D2 receptor, μ-opioid receptor, veratridine site of voltage-gated sodium channels, serotonin transporter, norepinephrine transporter, and dopamine transporter. It is an antagonist of the human 5-HT2A receptors with moderate affinity, although it is unclear if this is significant for its pharmacological actions given its much stronger activity at adrenergic receptors. Carvedilol reversibly binds to β-adrenergic receptors on cardiac myocytes. Inhibition of these receptors prevents a response to the sympathetic nervous system, leading to decreased heart rate and contractility. This action is beneficial in heart failure patients where the sympathetic nervous system is activated as a compensatory mechanism. Carvedilol blockade of α1-adrenergic receptors causes vasodilation of blood vessels. This inhibition leads to decreased peripheral vascular resistance and an antihypertensive effect.
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-amino-acid peptide originally purified from a bovine thymic extract and later produced synthetically. It is studied mainly for its effects on immune cell function.