PTMA gene raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-07-09. Anything still debated is marked as such rather than presented as settled.
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.
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 |
|---|---|---|
| Amino acid length | 28 residues | Single chain with an acetylated N-terminus |
| Molecular mass | Approximately 3,108 Da | Small shifts occur with counter-ion and water content |
| Isoelectric point | Around 3.5 | Low value follows from the many acidic residues |
| Parent molecule | N-terminal region of prothymosin alpha | Free circulating form in humans is not firmly established |
| Common synonyms | Thymalfasin; T alpha 1 | Older literature also uses the full spelled-out form |
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.
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.
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.
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。
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 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.
== General references == Acheson, D. J. (1990), Elementary Fluid Dynamics, Oxford Applied Mathematics and Computing Science Series, Oxford University Press, ISBN 978-0-19-859679-0 Batchelor, G. K. (1967), An Introduction to Fluid Dynamics, Cambridge University Press, ISBN 978-0-521-66396-0 Currie, I. G. (1974), Fundamental Mechanics of Fluids, McGraw-Hill, ISBN 978-0-07-015000-3 V. Girault and P. A. Raviart. Finite Element Methods for Navier–Stokes Equations: Theory and Algorithms. Springer Series in Computational Mathematics. Springer-Verlag, 1986 Landau, L. D.; Lifshitz, E. M. (1987), Fluid mechanics, vol. Course of Theoretical Physics Volume 6 (2nd revised ed.), Pergamon Press, ISBN 978-0-08-033932-0, OCLC 15017127 Polyanin, A. D.; Kutepov, A. M.; Vyazmin, A. V.; Kazenin, D. A. (2002), Hydrodynamics, Mass and Heat Transfer in Chemical Engineering, Taylor & Francis, London, ISBN 978-0-415-27237-7 Rhyming, Inge L. (1991), Dynamique des fluides, Presses polytechniques et universitaires romandes Smits, Alexander J. (2014), A Physical Introduction to Fluid Mechanics, Wiley, ISBN 0-47-1253499 Temam, Roger (1984): Navier–Stokes Equations: Theory and Numerical Analysis, ACM Chelsea Publishing, ISBN 978-0-8218-2737-6 Milne-Thomson, L.M., C.B.E (1962), Theoretical Hydrodynamics, Macmillan & Company Limited Tartar, L (2006), An Introduction to Navier Stokes Equation and Oceanography, Springer ISBN 3-540-35743-2 Birkhoff, Garrett (1960), Hydrodynamics, Princeton University Press Campos, D.
== Genetically encoding the aldehyde tag == The formylglycine tag or aldehyde tag is a convenient 6- or 13-amino acids long tag fused to a protein of interest. The 6-mer tag represents the small core consensus sequence and the 13-mer tag the longer full motif. The experiments on the genetically encoded aldehyde tag by clearly showed the high conversion efficiency with only the core consensus sequence present. Four proteins were produced recombinantly in E.coli with an 86% efficiency of for the full-length motif and >90% efficiency for the 6-mer determined by mass spectrometry. The size of the sequence is analogous to the commonly used 6x His-Tag and has the advantage that it can also be genetically encoded. The sequence is recognized in the ER solely depending on primary sequence and subsequently targeted by FGE. Notably, in the setup of recombinant expression proteins in E. coli a coexpression of exogenous FGE aids full conversion, although E. coli has endogenous FGE-activity. The introduction of an aldehyde tag has a workflow that consists of three segments: A the expression of the fusion protein, that carries the peptide tag derived from the sulfatase motif, B the enzymatic conversion of Cys to f(Gly) and C the bioorthogonal probing with hydrazides or alkoxy amines (Fig. 1).
=== EC 1.17.98 With other, known, physiological acceptors === EC 1.17.98.1: bile-acid 7α-dehydroxylase. Now known to be catalyzed by multiple enzymes. EC 1.17.98.2: bacteriochlorophyllide c C-71-hydroxylase EC 1.17.98.3: formate dehydrogenase (coenzyme F420) EC 1.17.98.4: formate dehydrogenase (hydrogenase)
TGI Fridays Franchisor, LLC, doing business as TGI Fridays, is an American casual dining restaurant chain focusing primarily on American cuisine. The restaurant's name stands for "Thank God It's Friday". TGI Fridays operates more than 380 locations in more than 35 countries, including 69 in the United States. The chain filed for bankruptcy in the United States on November 2, 2024.
Froud, Kristina E.; Wardhaugh, Tina; Banks, Duncan; Saffrey, M. Jill; Stewart, Michael G. (2010). "Colostrinin™ Alleviates Amyloid-β Induced Toxicity in Rat Primary Hippocampal Cultures" (PDF). Journal of Alzheimer's Disease. 20 (2): 423–426. doi:10.3233/JAD-2010-1382. PMID 20164569.
Sources: en.wikipedia.org
==== Dose ==== A milliliter of pure GBL metabolizes to the equivalent 1.65 g of NaGHB, the common form, so doses are measured in the single milliliter range, either taken all at once or sipped over the course of a night.
Due to a series of German victories on the Eastern Front, the area of Congress Poland became occupied by the Central Powers of Germany and Austria; Warsaw was captured by the Germans on 5 August 1915. In the Act of 5th November 1916, a fresh incarnation of the Kingdom of Poland (Królestwo Regencyjne) was proclaimed by Germany and Austria on formerly Russian-controlled territories, within the German Mitteleuropa scheme. The sponsor states were never able to agree on a candidate to assume the throne, however; rather, it was governed in turn by German and Austrian governor-generals, a Provisional Council of State, and a Regency Council. This increasingly autonomous puppet state existed until November 1918, when it was replaced by the newly established Republic of Poland. The existence of this "kingdom" and its planned Polish army had a positive effect on the Polish national efforts on the Allied side, but in the Treaty of Brest-Litovsk of March 1918 the victorious in the east Germany imposed harsh conditions on defeated Russia and ignored Polish interests. Toward the end of the war, the German authorities engaged in massive, purposeful devastation of industrial and other economic potential of Polish lands in order to impoverish the country, a likely future competitor of Germany.
The two basic categories of tequila are mixtos and 100% agave. Mixtos use no less than 51% agave, with other sugars making up the remainder. Mixtos use both glucose and fructose sugars. There are five categories of tequila defined by the NOM:
=== Kidney disease === Patients with chronic kidney disease and end-stage renal disease are at higher risk for infections, and procalcitonin has been studied in these populations, who often have higher levels. Procalcitonin can be dialyzed, and so levels are dependent upon when patients receive hemodialysis. While there is no formally accepted cutoff value for patients undergoing HD, using a value of greater or equal to 0.5 ng/mL yielded a sensitivity of 97-98% and a specificity of 70-96%.
Sources: en.wikipedia.org
An alternative picoinjection method involves utilizing the injection reagent as the conductor of an electric field where a voltage applied to the fluid stimulates injection. Such a method also allows for greater control of injection as the voltage applied corresponds to the volume of reagent fluid injected. Droplet-to-droplet contamination is a challenge of many injection methods. To combat this, Doonan et al. developed a multifunctional K-channel, which flows reagent streams opposite the path of the droplet stream. Utilizing an interface between the two channels, injection is achieved similarly to picoinjection, but any bilateral contamination washed away through continuous reagent flow. Contamination is avoided at the expense of potentially wasting precious reagent.
Those who perform floor and other surface cleaning tasks (e.g., floor waxing) and who use quaternary ammonium, alcohol, and chlorine-based products are associated with a higher VOC exposure than the two previous groups, that is, they are particularly linked to exposure to acetone, chloroform, α-pinene, 2-propanol or d-limonene. Other healthcare environments such as nursing and age care homes have been rarely a subject of study, even though the elderly and vulnerable populations may spend considerable time in these indoor settings where they might be exposed to VOCs, derived from the common use of cleaning agents, sprays and fresheners. In one study, more than 200 chemicals were identified, of which 41 have adverse health effects, 37 of them being VOCs. The health effects include skin sensitization, reproductive and organ-specific toxicity, carcinogenicity, mutagenicity, and endocrine-disrupting properties. Furthermore, in another study carried out in the same European country, it was found that there is a significant association between breathlessness in the elderly population and elevated exposure to VOCs such as toluene and o-xylene, unlike the remainder of the population.
high-affinity glutamate and neutral amino acid transporter (SLC1A1, SLC1A2, SLC1A3, SLC1A4, SLC1A5, SLC1A6, SLC1A7) facilitative GLUT transporter (SLC2A1, SLC2A2, SLC2A3, SLC2A4, SLC2A5, SLC2A6, SLC2A7, SLC2A8, SLC2A9, SLC2A10, SLC2A11, SLC2A12, SLC2A13, SLC2A14) heavy subunits of heterodimeric amino acid transporters (SLC3A1, SLC3A2) bicarbonate transporter (SLC4A1, SLC4A2, SLC4A3, SLC4A4, SLC4A5, SLC4A6, SLC4A7, SLC4A8, SLC4A9, SLC4A10, SLC4A11) sodium glucose cotransporter (SLC5A1, SLC5A2, SLC5A3, SLC5A4, SLC5A5, SLC5A6, SLC5A7, SLC5A8, SLC5A9, SLC5A10, SLC5A11, SLC5A12) sodium- and chloride-dependent sodium:neurotransmitter symporters (SLC6A1, SLC6A2, SLC6A3, SLC6A4, SLC6A5, SLC6A6, SLC6A7, SLC6A8, SLC6A9, SLC6A10, SLC6A11, SLC6A12, SLC6A13, SLC6A14, SLC6A15, SLC6A16, SLC6A17, SLC6A18, SLC6A19, SLC6A20) cationic amino acid transporter/glycoprotein-associated cationic amino acid transporters (SLC7A1, SLC7A2, SLC7A3, SLC7A4) glycoprotein-associated/light or catalytic subunits of heterodimeric amino acid transporters (SLC7A5, SLC7A6, SLC7A7, SLC7A8, SLC7A9, SLC7A10, SLC7A11, SLC7A13, SLC7A14) Na+/Ca2+ exchanger (SLC8A1, SLC8A2, SLC8A3) Na+/H+ exchanger (SLC9A1, SLC9A2, SLC9A3, SLC9A4, SLC9A5, SLC9A6, SLC9A7, SLC9A8, SLC9A9, SLC9A10, SLC9A11, SLC9B1, SLC9B2) sodium bile salt cotransport (SLC10A1, SLC10A2, SLC10A3, SLC10A4, SLC10A5, SLC10A6, SLC10A7) proton coupled metal ion transporter (SLC11A1, SLC11A2) electroneutral cation-Cl cotransporter (SLC12A1, SLC12A2, SLC12A3, SLC12A4, SLC12A5, SLC12A6, SLC12A7, SLC12A8, SLC12A9) Na+-sulfate/carboxylate cotransporter (SLC13A1, SLC13A2, SLC13A3, SLC13A4, SLC13A5) urea transporter (SLC14A1, SLC14A2) proton oligopeptide cotransporter (SLC15A1, SLC15A2, SLC15A3, SLC15A4) monocarboxylate transporter (SLC16A1, SLC16A2, SLC16A3, SLC16A4, SLC16A5, SLC16A6, SLC16A7, SLC16A8, SLC16A9, SLC16A10, SLC16A11, SLC16A12, SLC16A13, SLC16A14) vesicular glutamate transporter (SLC17A1, SLC17A2, SLC17A3, SLC17A4, SLC17A5, SLC17A6, SLC17A7, SLC17A8, SLC17A9) vesicular amine transporter (SLC18A1, SLC18A2, SLC18A3) folate/thiamine transporter (SLC19A1, SLC19A2, SLC19A3) type III Na+-phosphate cotransporter (SLC20A1, SLC20A2) organic anion transporting subfamily 1 (SLCO1A2, SLCO1B1, SLCO1B3, SLCO1C1) subfamily 2 (SLCO2A1, SLCO2B1) subfamily 3 (SLCO3A1) subfamily 4 (SLCO4A1, SLCO4C1) subfamily 5 (SLCO5A1) subfamily 6 (SLCO6A1) organic cation/anion/zwitterion transporter (SLC22A1, SLC22A2, SLC22A3, SLC22A4, SLC22A5, SLC22A6, SLC22A7, SLC22A8, SLC22A9, SLC22A10, SLC22A11, SLC22A12, SLC22A13, SLC22A14, SLC22A15, SLC22A16, SLC22A17, SLC22A18, SLC22A18AS, SLC22A19, SLC22A20, SLC22A23, SLC22A24, SLC22A25, SLC22A31) Na+-dependent ascorbic acid transporter (SLC23A1, SLC23A2, SLC23A3, SLC23A4) Na+/(Ca2+-K+) exchanger (SLC24A1, SLC24A2, SLC24A3, SLC24A4, SLC24A5, SLC24A6) mitochondrial carrier (SLC25A1, SLC25A2, SLC25A3, SLC25A4, SLC25A5, SLC25A6, UCP1(SLC25A7), UCP2(SLC25A8), UCP3(SLC25A9), SLC25A10, SLC25A11, SLC25A12, SLC25A13, SLC25A14, SLC25A15, SLC25A16, SLC25A17, SLC25A18, SLC25A19, SLC25A20, SLC25A21, SLC25A22, SLC25A23, SLC25A24, SLC25A25, SLC25A26, SLC25A27, SLC25A28, SLC25A29, SLC25A30, SLC25A31, SLC25A32, SLC25A33, SLC25A34, SLC25A35, SLC25A36, SLC25A37, SLC25A38, SLC25A39, SLC25A40, SLC25A41, SLC25A42, SLC25A43, SLC25A44, SLC25A45, SLC25A46), SLC25A47, SLC25A48, MTCH1(SLC25A49), MTCH2(SLC25A50), SLC25A51, SLC25A52, SLC25A53 multifunctional anion exchanger (SLC26A1, SLC26A2, SLC26A3, SLC26A4, SLC26A5, SLC26A6, SLC26A7, SLC26A8, SLC26A9, SLC26A10, SLC26A11) fatty acid transport proteins (SLC27A1, SLC27A2, SLC27A3, SLC27A4, SLC27A5, SLC27A6) Na+-coupled nucleoside transport (SLC28A1, SLC28A2, SLC28A3) facilitative nucleoside transporter (SLC29A1, SLC29A2, SLC29A3, SLC29A4) zinc transporter (SLC30A1, SLC30A2, SLC30A3, SLC30A4, SLC30A5, SLC30A6, SLC30A7, SLC30A8, SLC30A9, SLC30A10) copper transporter (SLC31A1, SLC31A2) vesicular inhibitory amino acid transporter (SLC32A1) Acetyl-CoA transporter (SLC33A1) type II Na+-phosphate cotransporter (SLC34A1, SLC34A2, SLC34A3) nucleotide-sugar transporter subfamily A (SLC35A1, SLC35A2, SLC35A3, SLC35A4, SLC35A5) subfamily B (SLC35B1, SLC35B2, SLC35B3, SLC35B4) subfamily C (SLC35C1, SLC35C2) subfamily D (SLC35D1, SLC35D2, SLC35D3) subfamily E (SLC35E1, SLC35E2A, SLC35E2B, SLC35E3, SLC35E4) subfamily F (SLC35F1, SLC35F2, SLC35F3, SLC35F4, SLC35F5) subfamily G (SLC35G1, SLC35G3, SLC35G4, SLC35G5, SLC35G6) proton-coupled amino acid transporter (SLC36A1, SLC36A2, SLC36A3, SLC36A4) sugar-phosphate/phosphate exchanger (SLC37A1, SLC37A2, SLC37A3, SLC37A4) System A & N, sodium-coupled neutral amino acid transporter (SLC38A1, SLC38A2, SLC38A3, SLC38A4, SLC38A5, SLC38A6, SLC38A7, SLC38A8, SLC38A9, SLC38A10, SLC38A11) metal ion transporter (SLC39A1, SLC39A2, SLC39A3, SLC39A4, SLC39A5, SLC39A6, SLC39A7, SLC39A8, SLC39A9, SLC39A10, SLC39A11, SLC39A12, SLC39A13, SLC39A14) basolateral iron transporter (SLC40A1) MgtE-like magnesium transporter (SLC41A1, SLC41A2, SLC41A3) Ammonia transporter (RHAG(SLC42A1), RHBG(SLC42A2), RHCG(SLC42A3)) Na+-independent, system-L like amino acid transporter (SLC43A1, SLC43A2, SLC43A3) Choline-like transporter (SLC44A1, SLC44A2, SLC44A3, SLC44A4, SLC44A5) Putative sugar transporter (SLC45A1, SLC45A2, SLC45A3, SLC45A4) Folate transporter (SLC46A1, SLC46A2, SLC46A3) multidrug and toxin extrusion (SLC47A1, SLC47A2) Heme transporter family (SLC48A1) Heme transporter (FLVCR1(SLC49A1), FLVCR2(SLC49A2), SLC49A3, SLC49A4) Sugar efflux transporters of the SWEET family (SLC50A1) Transporters of steroid-derived molecules (SLC51A, SLC51B) Riboflavin transporter family RFVT/SLC52 (SLC52A1, SLC52A2, SLC52A3) Phosphate carriers (XPR1(SLC53A1)) Mitochondrial pyruvate carriers (MPC1(SLC54A1), MPC2(SLC54A2), MPC1L(SLC54A3)) Mitochondrial cation/proton exchangers (LETM1(SLC55A1), LETM2(SLC55A2), LETMD1(SLC55A3)) Sideroflexins (SFXN1(SLC56A1), SFXN2(SLC56A2), SFXN3(SLC56A3), SFXN4(SLC56A4), SFXN5(SLC56A5)) NiPA-like magnesium transporter family (NIPA1(SLC57A1), NIPA2(SLC57A2), NIPAL1(SLC57A3), NIPAL2(SLC57A4), NIPAL3(SLC57A5), NIPAL4(SLC57A6)) MagT-like magnesium transporter family (MAGT1(SLC58A1), TUSC3(SLC58A2)) Sodium-dependent lysophosphatidylcholine symporter family (MFSD2A(SLC59A1), MFSD2B(SLC59A2)) Glucose transporters (MFSD4A(SLC60A1), MFSD4B(SLC60A2)) Molybdate transporter family (MFSD5(SLC61A1)) Pyrophosphate transporters (ANKH(SLC62A1)) Sphingosine-phosphate transporters (SPNS1(SLC63A1), SPNS2(SLC63A2), SPNS3(SLC63A3)) Golgi Ca2+/H+ exchangers (TMEM165(SLC64A1)) NPC-type cholesterol transporters (NPC1(SLC65A1), NPC1L1(SLC65A2)) Cationic amino acid exporters (SLC66A1, SLC66A2, SLC66A3, CTNS(SLC66A4), MPDU1(SLC66A5))
Sources: en.wikipedia.org
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.
Prothymosin alpha is a much larger acidic protein, roughly 111 to 113 residues long, and the thymosin alpha-1 sequence matches its N-terminal region. The small peptide is therefore best understood as a fragment of that parent protein rather than a separate gene product.
Trials and clinical reports have examined chronic hepatitis B and C, use as a vaccine adjuvant, and supportive treatment in some immunodeficiency and oncology settings. Results vary by indication, and regulatory approval differs between countries.
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.