A practical reference on 细胞因子: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-03-06 and is reviewed periodically as new material appears.
Identity and purity are usually checked by reverse-phase high-performance liquid chromatography, which separates the intact chain from truncated products, together with mass spectrometry for confirmation of the expected mass. Peptide mapping after enzymatic digestion and amino acid analysis add sequence-level evidence. Release testing also covers water content, residual solvents, and counter-ions, all of which influence measured mass and stability. Related-peptide limits are commonly expressed as a percentage of total peak area, with individual unspecified impurities held below a lower threshold.
The lyophilized peptide is a white to off-white powder that dissolves freely in water and in aqueous buffers near neutral pH. Because the molecule carries a net negative charge under physiological conditions, saline and phosphate solutions are the usual vehicles, while strongly acidic media are avoided. Stock solutions are commonly divided into small aliquots so that repeated freezing and thawing can be limited, since cycling may encourage aggregation. Solubility in organic solvents is poor and those solvents are seldom used as primary diluents.
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.
Thymosin alpha 1 is a short peptide first isolated from bovine thymus tissue in the early 1970s during fractionation work aimed at identifying factors that influence T cell development. It belongs to a family of acidic thymic peptides, and the original preparations contained several components that were later separated by chromatography. The compound is now produced synthetically rather than extracted from tissue, which removes batch variability tied to animal sourcing. Researchers describe it as an immunomodulatory peptide because laboratory studies show effects on several cell types of the innate and adaptive immune systems.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Assessed by visual inspection at release |
| Solubility class | Freely soluble in water | Aqueous buffers near neutral pH |
| Typical storage temperature | Minus 20 degrees Celsius | Lyophilized, desiccated, protected from light |
| Typical analytical method | Reverse-phase HPLC with mass spectrometry | Used together for purity and identity |
| Common synonyms | T-alpha-1; thymalfasin | Older reports use several designations |
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.
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.
Laboratory work indicates that the peptide acts on cells of both the innate and adaptive immune systems. Reported effects include signalling through Toll-like receptors on dendritic cells, enhanced T-cell maturation, and increased natural killer cell activity. These actions are described largely from cell-culture and animal experiments, and the precise receptor-level events remain incompletely defined. Studies in humans have generally measured immune markers rather than a single defined molecular target. The resulting picture remains partly descriptive.
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Results across trials have been mixed, and several studies were small or conducted under differing protocols. Regulatory status varies by country, and the compound is not approved in every jurisdiction where it is studied. Evidence for any single indication should be read with attention to sample size and endpoint choice.
Thymosin alpha-1 is a 28-residue peptide first isolated from thymus tissue in the 1970s. It corresponds to the N-terminal portion of thymosin beta-4, from which it is cleaved in vivo. The peptide carries an acetyl group at its N-terminus, a modification that affects its charge and stability. Synthetic material produced by solid-phase peptide synthesis is chemically identical to the natural fragment and is the form used in research and clinical studies.
临床研究将Tα1用于慢性病毒感染、肿瘤辅助治疗和疫苗佐剂等场景。部分试验报告了免疫学指标改善，但临床终点获益在不同研究中并不一致。系统综述指出，研究间在人群、剂量和联合方案上差异较大，难以汇总结论。因此，Tα1的确切临床地位仍属开放问题，需要更多高质量随机对照试验来澄清。其机制研究也需从体外实验向体内模型推进。
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。
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.
== Metal catalysts == Metals such as iron, copper, chromium, vanadium, and cobalt are capable of redox cycling in which a single electron may be accepted or donated by the metal. This action catalyzes production of reactive radicals and reactive oxygen species. The presence of such metals in biological systems in an uncomplexed form (not in a protein or other protective metal complex) can significantly increase the level of oxidative stress. These metals are thought to induce Fenton reactions and the Haber-Weiss reaction, in which hydroxyl radical is generated from hydrogen peroxide. The hydroxyl radical then can modify amino acids. For example, meta-tyrosine and ortho-tyrosine form by hydroxylation of phenylalanine. Other reactions include lipid peroxidation and oxidation of nucleobases. Metal-catalyzed oxidations also lead to irreversible modification of arginine, lysine, proline, and threonine. Excessive oxidative-damage leads to protein degradation or aggregation. The reaction of transition metals with proteins oxidized by reactive oxygen or nitrogen species can yield reactive products that accumulate and contribute to aging and disease. For example, in Alzheimer's patients, peroxidized lipids and proteins accumulate in lysosomes of the brain cells.
This should be able to happen in prebiotically plausible conditions with high rates of copying accuracy to prevent degradation of information, but also allowing for the occurrence of occasional errors during the copying process to allow for Darwinian evolution to proceed. Attempts have been made to develop ribozymes as therapeutic agents, as enzymes which target defined RNA sequences for cleavage, as biosensors, and for applications in functional genomics and gene discovery.
== List of women chemists == The following list is split into the centuries when the majority of the scientist's work was performed. The scientist's listed may be born and perform work outside of the century they are listed under.
=== Filming === Filming began in March 2019 with Glen Winter directing the pilot. Christopher Manley and Scott Peck were directors of photography on the series. Filming occurred throughout the Atlanta metropolitan area, including: Marietta, Virginia–Highland, Duluth, Lithia Springs, Dallas, Marietta Square, West End, Westlake High School, the Atlanta Center for Medical Research, Campbell Middle School, Paulding County, Smyrna, Arbor Place Mall, Vinings, Mableton, and Douglas County High School. Walter Garcia served as the series' stunt coordinator and second-unit director. He was hired to help Stargirl's staff "have a personality and be alive when she fights with it". The series continued to film in Atlanta for the second season, with filming beginning by October 28, 2020.
Hooters is the registered trademark used by an international restaurant chain Hooters, Inc., based in Clearwater, Florida and its associated franchise group Hoot Owl Restaurants LLC. The Hooters name is a double entendre referring to both an American slang term for women's breasts and the logo (a bird known for its "hooting" calls: the owl). The waiting staff at Hooters restaurants are primarily young women, usually referred to simply as "Hooters Girls", whose revealing outfits and sex appeal are played up and are a primary component of the company's image. The company employs both men and women as cooks, hosts (at some franchises), busboys, and managers. The menu includes hamburgers and other sandwiches, steaks, seafood entrees, appetizers, and the restaurant's specialty, chicken wings. Almost all Hooters restaurants hold alcoholic beverage licenses to sell beer and wine, and where local permits allow, a full liquor bar. Hooters T-shirts, sweatshirts, and various souvenirs and curios are also sold.
Sources: en.wikipedia.org
The hydrostatic effect of variable ballast tanks is not the only way to control the submarine underwater. Hydrodynamic maneuvering is done by several control surfaces, collectively known as diving planes or hydroplanes, which can be moved to create hydrodynamic forces when a submarine moves longitudinally at sufficient speed. In the classic cruciform stern configuration, the horizontal stern planes serve the same purpose as the trim tanks, controlling the trim. Most submarines additionally have forward horizontal planes, normally placed on the bow until the 1960s but often on the sail on later designs, where they are closer to the center of gravity and can control depth with less effect on the trim.
The Journal of Biological Chemistry publishes research in any area of biochemistry or molecular biology in one online-only issue per week. Molecular & Cellular Proteomics is a monthly online only publication. Articles appearing in MCP "...describe the structural and functional properties of proteins and their expression, particularly with respect to the developmental time courses of the organism of which they are a part." The journal also publishes other content such as "HUPO views" (reports from the Human Proteome Organization), proceedings from HUPO meetings, and the proceedings of the International Symposium On Mass Spectrometry In The Life Sciences. The Journal of Lipid Research covers "...the science of lipids in health and disease. The Journal emphasizes lipid function and the biochemical and genetic regulation of lipid metabolism. In addition, JLR publishes manuscripts on patient-oriented and epidemiological research relating to altered lipid metabolism, including modification of dietary lipids." ASBMB Today is the society's monthly news magazine. It contains extensive coverage of awards, meetings, research highlights, job placement advertising and human interest articles. All ASBMB members receive a complimentary subscription to ASBMB Today. The online version of the magazine features daily publishing.
Normal phase elution is achieved by pumping the non-aqueous or phase of a biphasic solvent system through the column as the mobile phase, with a more polar stationary phase being retained in the column. The cause of original nomenclature of is relevant. As original stationary phases of paper chromatography were superseded by more efficient materials such as diatomaceous earths (natural micro-porous silica) and followed by modern silica gel, the thin-layer chromatography stationary phase was polar (hydroxy groups attached to silica) and maximum retention was achieved with non-polar solvents such as n-hexane. Progressively more polar eluents were then used to move polar compounds up the plate. Various alkane bonded phases were tried with C18 becoming the most popular. Alkane chains were chemically bonded to the silica, and a reversal of the elution trend occurred. Thus a polar stationary became "normal" phase chromatography, and the non-polar stationary phase chromatography became "reversed" phase chromatography.
=== Phosphorus-32 === 32P is a radioactive isotope of phosphorus with relative atomic mass 31.973907 Da and half-life of 14.26 days. 32P is a radioactive isotope of phosphorus with beta particle-emitting radiocytotoxic activity. Emitted by 32P, beta particles directly damage cellular DNA and, by ionizing intracellular water to produce several types of cytotoxic free radicals and superoxides, indirectly damage intracellular biological macromolecules, resulting in tumor cell death.
represent the molar masses of the gases. This equation is known as Graham's law of effusion. The effusion rate for a gas depends directly on the average velocity of its particles. Thus, the faster the gas particles are moving, the more likely they are to pass through the effusion orifice.
Sources: en.wikipedia.org
Barnsley Football Club is a professional football club in Barnsley, South Yorkshire, England. The club competes in EFL League One, the third tier of English football. Nicknamed “the Reds”, "the Tykes" or less commonly "the Colliers", they were founded in 1887 by Reverend Tiverton Preedy and moved to Oakwell the following year. The club's original blue colours were changed to red and white in 1904. Barnsley spent the 1890s in the Sheffield & District, Midland and Yorkshire leagues, before gaining admittance to the Football League Second Division in 1898. They twice reached the final of the FA Cup whilst still in the second tier, losing to Newcastle United in 1910 and winning the competition over West Bromwich Albion in 1912. The club suffered relegation in 1933, but secured promotion as Third Division North champions in 1934. They won the Third Division North title for a second time in 1939, having been relegated the previous season. Relegated again in 1953, they secured another Third Division North title in 1955. However, further relegations left them in the fourth tier of English football by 1966. Promotion from the Fourth Division was achieved in 1968, though they were relegated after just four seasons. The club secured two promotions in three years under the stewardship of Allan Clarke and Norman Hunter, and from 1981 would spend sixteen consecutive years in the second tier. Premier League football was secured for the 1997–98 season with a second-place finish in the First Division, though they were relegated after one season and dropped down to the third tier in 2002.
In situations where the partial pressure of oxygen in the water is low, diffusion of oxygen into the blood is reduced, Henry's law can explain this phenomenon. The law states that at equilibrium, the partial pressure of oxygen in water will be equal to that in air; but the concentrations will differ due to the differing solubility. This law explains why O. vulgaris has to alter the amount of water cycled through its mantle cavity as the oxygen concentration in water changes. The gills are in direct contact with water – carrying more oxygen than the blood – that has been brought into the mantle cavity of the octopus. Gill capillaries are quite small and abundant, which creates an increased surface area that water can come into contact with, thus resulting in enhanced diffusion of oxygen into the blood. Some evidence indicates that lamellae and vessels within the lamellae on the gills contract to aid in propelling blood through the capillaries.
=== Performing arts and cinema === Moscow is the heart of Russian performing arts, including ballet and cinema: 68 museums, 103 theaters, 132 cinemas, and 24 concert halls. Among Moscow's theaters and ballet studios are the Bolshoi Theatre, the Malyi Theatre, the Vakhtangov Theatre, and the Moscow Art Theatre. The Moscow International Performance Arts Center, opened in 2003—also called the Moscow International House of Music—is known for classical music performances. This center contains Russia's largest organ, which is installed in Svetlanov Hall. In addition, Moscow contains two large circuses: the Moscow State Circus and the Moscow Circus on Tsvetnoy Boulevard (also called Nikulin's Circus, after Yuri Nikulin). The Mosfilm studio was at the heart of many classic films, as it has been responsible for both artistic and mainstream productions. However, despite the ongoing participation and reputation of internationally known Russian filmmakers, previously prolific domestic studios have become less active. The Salut cinema screens rare and historical films, and films from the Museum of Cinema are regularly shown. International film festivals are held in Moscow, including the Moscow International Film Festival, Stalker (focusing on human rights), Artdocfest (focusing on documentaries), and the Moscow Jewish Film Festival.
Mutations in the GSS gene cause glutathione synthetase deficiency. This gene provides instructions for making the enzyme glutathione synthetase. This enzyme is involved in a process called the gamma-glutamyl cycle, which takes place in most of the body's cells. This cycle is necessary for producing a molecule called glutathione. Glutathione protects cells from damage caused by unstable oxygen-containing molecules, which are byproducts of energy production. Glutathione is called an antioxidant because of its role in protecting cells from the damaging effects of these unstable molecules which are byproducts of energy production. Mutations in the GSS gene prevent cells from making adequate levels of glutathione, leading to the signs and symptoms of glutathione synthetase deficiency. This disorder is inherited in an autosomal recessive pattern, which means the defective gene is located on an autosome, and two copies of the gene - one from each parent - are required to be born with the disorder. The parents of an individual with an autosomal recessive disorder each carry one copy of the defective gene, but usually are not affected by the disorder.
Sources: en.wikipedia.org
Reconstituted solutions are typically kept refrigerated at two to eight degrees Celsius when used within a short window, or frozen in aliquots for longer periods. Repeated freeze-thaw cycles are avoided because they can reduce recovery of intact peptide.
It establishes that the measured mass matches the expected value for the intact molecule. It also helps detect modifications such as oxidation or truncation that shift the mass by a known amount.
Cycling between frozen and liquid states can promote aggregation and adsorption to container walls. Dividing a stock into single-use aliquots limits the number of cycles a given vial undergoes.
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.