If you have been reading about prothymosin alpha and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-06-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic peptide, 28 residues | N-terminal fragment of prothymosin alpha |
| Molecular mass | About 3108 Da | Acetylated form |
| Isoelectric point | Near 4.2 | Acidic peptide |
| Appearance | White to off-white lyophilized powder | Common supplied form |
| Typical storage | -20 °C or below, dry | Solution stability is lower |
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.
Like most short peptides, thymosin alpha-1 is susceptible to hydrolysis under strongly acidic or basic conditions and to oxidation when exposed to air over long periods. The acetylated amino terminus blocks one common degradation route, which contributes to the molecule's relative robustness in solution. Lyophilized material generally retains potency for extended periods when kept cold and dry. Once reconstituted, aqueous solutions are less stable and are typically used within a defined window rather than held indefinitely at ambient temperature.
Routine handling calls for storage of the lyophilized powder at refrigerated temperatures, away from light, in a sealed container. Working solutions are often prepared in sterile water or buffer and kept cold between uses. Repeated freeze-thaw cycles are generally avoided because they can promote aggregation and loss of material. Laboratories usually record lot number, reconstitution date, and storage conditions so that any change in behavior can be traced to a specific preparation.
Phagocytes (i.e. neutrophils and macrophages) require an enzyme to produce reactive oxygen species to destroy bacteria after they are ingested (phagocytosis), a process known as the respiratory burst. This enzyme is termed "phagocyte NADPH oxidase" (PHOX). This enzyme oxidizes NADPH and reduces molecular oxygen to produce superoxide anions, a reactive oxygen species. Superoxide is then disproportionated into peroxide and molecular oxygen by superoxide dismutase. Finally, peroxide is used by myeloperoxidase to oxidize chloride ions into hypochlorite (the active component of bleach), which is toxic to bacteria. Thus, NADPH oxidase is critical for phagocyte killing of bacteria through reactive oxygen species. (Two other mechanisms are used by phagocytes to kill bacteria: nitric oxide and proteases, but the loss of ROS-mediated killing alone is sufficient to cause chronic granulomatous disease.) Defects in one of the four essential subunits of phagocyte NADPH oxidase (PHOX) can all cause CGD of varying severity, dependent on the defect. There are over 410 known possible defects in the PHOX enzyme complex that can lead to chronic granulomatous disease.
Physical optics: The intensity of electromagnetic radiation such as light or X-rays or gamma rays in an absorbent medium, follows an exponential decrease with distance into the absorbing medium. This is known as the Beer-Lambert law. Radioactivity: In a sample of a radionuclide that undergoes radioactive decay to a different state, the number of atoms in the original state follows exponential decay as long as the remaining number of atoms is large. The decay product is termed a radiogenic nuclide. Thermoelectricity: The decline in resistance of a Negative Temperature Coefficient Thermistor as temperature is increased. Vibrations: Some vibrations may decay exponentially; this characteristic is often found in damped mechanical oscillators, and used in creating ADSR envelopes in synthesizers. An overdamped system will simply return to equilibrium via an exponential decay. Beer froth: Arnd Leike, of LMU Munich, won an Ig Nobel Prize for demonstrating that beer froth obeys the law of exponential decay. Automobile braking is a universal example of exponential decay, and variation of the mathematical exponentials and functions which the foot applies are important to the comfort of the occupants and the avoidance of accidents.
Terrestrial plants make leaf waxes to coat the surfaces of their leaves, to minimize water loss. These waxes are largely straight-chain n-alkyl lipids. They are insoluble, non-volatile, chemically inert, and resistant to degradation, making them easily preserved in the sedimentary record, and therefore good targets as biomarkers. The main water source for land plants is soil water, which largely resembles the HIC of rain water, but varies between environments and with enrichment by precipitation, depletion by evaporation, and exchange with atmospheric water vapor. There can be a significant offset between the δD value of source water and the δD value of leaf water at the site of lipid biosynthesis. No fractionation is associated with water uptake by roots, a process usually driven by capillary tension, with the one exception of xerophytes that burn ATP to pump water in extremely arid environments (with a roughly 10‰ depletion). However, leaf water can be substantially enriched relative to soil water due to transpiration, an evaporative process which is influenced by temperature, humidity, and the composition of surrounding water vapor. The leaf water HIC can be described with a modified Craig-Gordon model, where ΔDe is the steady state enrichment of leaf water, εeq is the temperature-dependent equilibrium fractionation between liquid water and vapor, εk is the KIE from diffusion between leaf internal air space and the atmosphere, ΔDv is the leaf/air disequilibrium, ea is atmospheric vapor pressure, and ei is internal leaf vapor pressure.
Sources: en.wikipedia.org
He also appeared on special episodes, like Raw's 25th anniversary episode, Raw Reunion, In 2022, Austin had his first feud since his retirement with Kevin Owens. At WrestleMania 38, Austin defeated Owens in a No Holds Barred match, his first match in 19 years.
Diethyltryptamine (DET), also known as N,N-diethyltryptamine or T-9, is a psychedelic drug of the tryptamine family closely related to dimethyltryptamine (DMT). It is taken orally, but can also be used by parenteral routes. The drug acts as a non-selective serotonin receptor agonist, including of the serotonin 5-HT2A receptor among others. It has not been found to occur endogenously. DET is a close structural homologue of DMT and dipropyltryptamine (DPT). Other analogues of DET include 4-HO-DET (ethocin), ethocybin (4-PO-DET), and 5-MeO-DET. DET was first synthesized in 1956 by Stephen Szára and subsequently described in material published in 1957. More systematic studies were reported later by Szára and colleagues and independently by Böszörményi and colleagues.
A β-helix is formed from repeating structural units consisting of two or three short β-strands linked by short loops. These units "stack" atop one another in a helical fashion so that successive repetitions of the same strand hydrogen-bond with each other in a parallel orientation. See the β-helix article for further information. In lefthanded β-helices, the strands themselves are quite straight and untwisted; the resulting helical surfaces are nearly flat, forming a regular triangular prism shape, as shown for the 1QRE archaeal carbonic anhydrase at right. Other examples are the lipid A synthesis enzyme LpxA and insect antifreeze proteins with a regular array of Thr sidechains on one face that mimic the structure of ice.
Sources: en.wikipedia.org
It corresponds to a fragment of the larger protein prothymosin alpha, which is present in many tissues. The isolated 28-amino-acid peptide was originally obtained from thymus preparations, and the pharmaceutical product is synthesized rather than extracted. The term therefore describes both a natural fragment and a manufactured drug substance.
Thymosin alpha-1 is a single defined 28-residue peptide, while the broader family includes unrelated peptides such as thymosin beta-4. The shared name reflects historical isolation from thymus tissue rather than a common structure. Confusion between the two is common in older literature.
No single pathway fully accounts for its reported effects. Several studies describe interaction with innate immune receptors and downstream cytokine changes, but the complete picture is not settled. Open questions remain about which effects occur at physiological concentrations.
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.