Immune modulation comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-12-27. Numbers and descriptions here follow the published literature rather than marketing material.
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。
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.
| 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 |
Within the immune system, the peptide acts on several cell types rather than a single target. Reported activities include promotion of T-cell maturation, enhancement of natural killer cell activity, and modulation of cytokine production by dendritic cells and macrophages. Some of these effects appear to operate through toll-like receptor signaling, though the precise receptor-level mechanism remains debated. Whether the observed immune changes translate into clinical benefit is a separate question and depends on the indication studied.
The peptide was described in the 1970s as a component of thymic extracts, and early research focused on restoring immune function in immunodeficiency states. A synthetic version entered clinical development in the 1980s and is approved as a drug in several countries for conditions such as chronic hepatitis B and certain immunodeficiencies. Approval status varies widely by jurisdiction, and in the United States it is not an approved therapeutic. Regulatory and clinical positions differ, so statements about efficacy should be tied to specific indications and studies.
Thymosin alpha-1 is a synthetic peptide of 28 amino acids, corresponding to the N-terminal fragment of prothymosin alpha. Its sequence begins with acetylation at the N-terminus, a modification that affects stability and receptor interaction. The peptide is acidic, with a calculated isoelectric point near 4.2, and carries no disulfide bonds, so its secondary structure is largely flexible in solution. Molecular mass is approximately 3108 daltons. The native form was first isolated from bovine thymus tissue, while pharmaceutical material is produced by solid-phase peptide synthesis.
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.
=== Thyroid inhibition === Perchlorate is a potent competitive inhibitor of the thyroid sodium-iodide symporter. Thus, it has been used to treat hyperthyroidism since the 1950s. At very high doses (70,000–300,000 ppb) the administration of potassium perchlorate was considered the standard of care in the United States, and remains the approved pharmacologic intervention for many countries. In large amounts perchlorate interferes with iodine uptake into the thyroid gland. In adults, the thyroid gland helps regulate the metabolism by releasing hormones, while in children, the thyroid helps in proper development. The NAS, in its 2005 report, Health Implications of Perchlorate Ingestion, emphasized that this effect, also known as Iodide Uptake Inhibition (IUI) is not an adverse health effect. However, in January 2008, California's Department of Toxic Substances Control stated that perchlorate is becoming a serious threat to human health and water resources. In 2010, the EPA's Office of the Inspector General determined that the agency's own perchlorate reference dose (RfD) of 24.5 parts per billion protects against all human biological effects from exposure, as the federal government is responsible for all US military base groundwater contamination. This finding was due to a significant shift in policy at the EPA in basing its risk assessment on non-adverse effects such as IUI instead of adverse effects.
Aspartate transaminase (AST) or aspartate aminotransferase, also known as AspAT/ASAT/AAT or (serum) glutamic oxaloacetic transaminase (GOT, SGOT), is a pyridoxal phosphate (PLP)-dependent transaminase enzyme (EC 2.6.1.1) that was first described by Arthur Karmen and colleagues in 1954. AST catalyzes the reversible transfer of an α-amino group between aspartate and glutamate and, as such, is an important enzyme in amino acid metabolism. AST is found in the liver, heart, skeletal muscle, kidneys, brain, red blood cells and gall bladder. Serum AST level, serum ALT (alanine transaminase) level, and their ratio (AST/ALT ratio) are commonly measured clinically as biomarkers for liver health. The tests are part of blood panels. The half-life of total AST in the circulation approximates 17 hours and, on average, 87 hours for mitochondrial AST. Aminotransferase is cleared by sinusoidal cells in the liver.
=== Primary concerns when using CDAs === The primary concerns to take into consideration when using a CDA in NMR spectroscopy are kinetic resolution, racemization during the derivatization reaction and that the reagent should have 100% optical purity. Kinetic resolution is especially significant when determining optical purity, but it is somewhat negligible when the CDA is being used to assign the absolute configuration of an optically pure substrate. Kinetic resolution can be overcome using excess of the CDA. Racemization can occur to either the CDA or the substrate and in both cases it has the potential to significantly affect the results.
== August 2013 interim report and governance charges == On 2 August 2013, almost seven months into the investigation, ASADA released an interim report to the AFL and Essendon Football Club. The interim report made no findings regarding the legality of the supplements program, but highlighted a wide range of governance and duty-of-care failures related to the program. On 13 August 2013, based on the interim report, AFL general counsel Andrew Dillon charged Essendon with "conduct that is unbecoming or likely to prejudice the interests or reputation of the Australian Football League or to bring the game of football into disrepute, contrary to AFL Rule 1.6". The charges included:
The reason that the set of vitamins skips directly from E to K is that the vitamins corresponding to letters F–J were either reclassified over time, discarded as false leads, or renamed because of their relationship to vitamin B, which became a complex of vitamins. The Danish-speaking scientists who isolated and described vitamin K (in addition to naming it as such) did so because the vitamin is intimately involved in the coagulation of blood following wounding (from the Danish word Koagulation). At the time, most (but not all) of the letters from F through to J were already designated, so the use of the letter K was considered quite reasonable. The table Nomenclature of reclassified vitamins lists chemicals that had previously been classified as vitamins, as well as the earlier names of vitamins that later became part of the B-complex. The missing numbered B vitamins were reclassified or determined not to be vitamins. For example, B9 is folic acid and five of the folates are in the range B11 through B16. Others, such as PABA (formerly B10), are biologically inactive, toxic, or with unclassifiable effects in humans, or not generally recognised as vitamins by science, such as the highest-numbered, which some naturopath practitioners call B21 and B22. There are also lettered B substances (e.g., Bm) listed at B vitamins that are not recognized as vitamins. There are other "D vitamins" now recognised as other substances, which some sources of the same type number up to D7. The controversial cancer treatment laetrile was at one point lettered as vitamin B17.
Sources: en.wikipedia.org
NAD(P)+ + a hydroquinone The 4 substrates of this enzyme are NADH, NADPH, H+, and quinone, whereas its 3 products are NAD+, NADP+, and hydroquinone. This enzyme belongs to the family of oxidoreductases, specifically those acting on NADH or NADPH with a quinone or similar compound as acceptor. The systematic name of this enzyme class is NAD(P)H:quinone oxidoreductase. Other names in common use include menadione reductase, phylloquinone reductase, quinone reductase, dehydrogenase, reduced nicotinamide adenine dinucleotide (phosphate,, quinone), DT-diaphorase, flavoprotein NAD(P)H-quinone reductase, menadione oxidoreductase, NAD(P)H dehydrogenase, NAD(P)H menadione reductase, NAD(P)H-quinone dehydrogenase, NAD(P)H-quinone oxidoreductase, NAD(P)H: (quinone-acceptor)oxidoreductase, NAD(P)H: menadione oxidoreductase, NADH-menadione reductase, naphthoquinone reductase, p-benzoquinone reductase, reduced NAD(P)H dehydrogenase, viologen accepting pyridine nucleotide oxidoreductase, vitamin K reductase, diaphorase, reduced nicotinamide-adenine dinucleotide (phosphate) dehydrogenase, vitamin-K reductase, NAD(P)H2 dehydrogenase (quinone), NQO1, QR1, and NAD(P)H:(quinone-acceptor) oxidoreductase. This enzyme participates in biosynthesis of steroids. It employs one cofactor, FAD. At least one compound, Dicumarol is known to inhibit this enzyme.
Protein–protein interactions often result in one of the interacting proteins either being 'activated' or 'repressed'. Such effects can be indicated in a PPI network by "signs" (e.g. "activation" or "inhibition"). Although such attributes have been added to networks for a long time, Vinayagam et al. (2014) coined the term Signed network for them. Signed networks are often expressed by labeling the interaction as either positive or negative. A positive interaction is one where the interaction results in one of the proteins being activated. Conversely, a negative interaction indicates that one of the proteins being inactivated. Protein–protein interaction networks are often constructed as a result of lab experiments such as yeast two-hybrid screens or 'affinity purification and subsequent mass spectrometry techniques. However these methods do not provide the layer of information needed in order to determine what type of interaction is present in order to be able to attribute signs to the network diagrams.
===== Iron import ===== Most cell types take up iron primarily through receptor-mediated endocytosis via transferrin receptor 1 (TFR1), transferrin receptor 2 (TFR2) and GAPDH. TFR1 has a 30-fold higher affinity for transferrin-bound iron than TFR2 and thus is the main player in this process. The higher order multifunctional glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) also acts as a transferrin receptor. Transferrin-bound ferric iron is recognized by these transferrin receptors, triggering a conformational change that causes endocytosis. Iron then enters the cytoplasm from the endosome via importer DMT1 after being reduced to its ferrous state by a STEAP family reductase. Alternatively, iron can enter the cell directly via plasma membrane divalent cation importers such as DMT1 and ZIP14 (Zrt-Irt-like protein 14). Again, iron enters the cytoplasm in the ferrous state after being reduced in the extracellular space by a reductase such as STEAP2, STEAP3 (in red blood cells), Dcytb (in enterocytes) and SDR2.
== Entertainment == Serbia and Montenegro participated in the Eurovision Song Contest on two occasions and in Junior Eurovision Song Contest 2005 only on one occasion. The country debuted in the Eurovision Song Contest under the name Serbia and Montenegro in 2004, when Željko Joksimović got second place. In 2006, the year of Montenegrin independence, the country Serbia and Montenegro did not have a representative due to the scandal in Evropesma 2006, but was still able to vote in both the semi-final and the final.
Sources: en.wikipedia.org
The roles of these residues are analogous or the same as the previously described Sortases, in that His and Asp play a supporting role in interacting with the target residue, while the Cys forms a thioester with a carboxyl group for a later nucleophilic attack by a primary amine, in this case due to interest that of Lysine. Though the similarities to sortase catalytically start to end there, as the enzyme and the family is dependent on calcium, which plays a crucial structural role in holding a tight conformation of the enzyme. The TGases, also have a very different substrate specificity in that they target specifically the middle Gln, in the sequence 'Gln-Gln-Val'. The general substrate specificity, i.e. the specific protein is due to the general structure of different TGases which targets them to the substrate. The specificity has been noted in TGases such that different TGases will react with different Gln's on the same protein, signifying that the enzymes have a very specific initial targeting. It has also been shown to have some specificity as to which target Lysine it transfers the protein to, as in the case of Factor XIII, where the adjacent residue to the Lys decides whether the reaction will occur. Thus while the TGases may initially seem like a eukaryotic sortase, they stand on their own as separate set of enzymes. Another case of an isopeptide linking enzyme for structural purposes is the actin cross-linking domain (ACD) of the MARTX toxin protein generated by V. cholerae.
== Management == Red ear syndrome has proven difficult to treat. The most widely attempted medication is gabapentin, with one case series finding that seven of eight patients on gabapentin showed improvement in attack frequency and ear color. Smaller studies have reported some success in certain patients using amitriptyline, flunarizine, imipramine, verapamil, propranolol and ibuprofen. Appropriate medication may differ depending on the underlying cause of the individual's symptoms. Using an ice pack to cool the ear during an attack can provide temporary relief.
An RNA helicase is an enzyme that unwinds RNA. The unwinding is powered by the helicase's hydrolysis of ATP. RNA helicases are involved holistically in the metabolism of RNA, which is found in all facets of life on Earth.
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 usually described as an immunomodulatory peptide rather than a classic circulating hormone. No endocrine gland is known to release it as a primary secretory product, and its measured presence in blood is not firmly established.