If you have been reading about thymosin alpha-1 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 2026-04-08. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Thymosin alpha-1 is supplied as a lyophilized powder in most research settings. The solid dissolves readily in water and in common aqueous buffers, and it is typically reconstituted shortly before use. Solutions are clear and colourless at ordinary working concentrations. Because the peptide is hygroscopic, weighing and reconstitution are usually performed with minimal exposure to ambient air. Aliquots are prepared to avoid repeated freeze-thaw cycles, and working solutions are kept cold.
Long-term storage is generally at minus twenty degrees Celsius or colder, preferably desiccated and protected from light. Lyophilized material is more stable than reconstituted solution, which degrades faster at room temperature. Stability depends on pH, ionic strength, and the presence of oxidising agents. Published stability data for the peptide are limited, so storage claims in catalogues should be treated as general guidance rather than measured guarantees. Freeze-thaw cycles are kept to a minimum.
| 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 |
Lyophilized material is typically treated as a hygroscopic solid that should be brought to room temperature before the container is opened, which limits condensation on the powder. Reconstitution is commonly done with sterile water or a buffered diluent, and gentle mixing is preferred over vigorous agitation to reduce foaming and surface adsorption. Because peptides can bind to plastic and glass, diluents containing a small amount of carrier protein are sometimes used in laboratory work. Working solutions are generally aliquoted and prepared fresh rather than subjected to repeated freezing and thawing.
Stability depends on temperature, pH, and the number of freeze-thaw events the sample has experienced. Freeze-dried material is commonly held at -20 °C or colder, while reconstituted liquid is kept cold and used within a short window. Extreme pH and prolonged light exposure can promote deamidation, oxidation, or aggregation, particularly at asparagine and methionine positions. Adsorption to container walls can lower the measured concentration of a dilute solution even when the peptide molecules themselves remain intact.
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.
Recommended storage for the dry powder is a freezer near minus twenty degrees Celsius, kept desiccated and away from light. Once dissolved, the peptide is less stable and is usually held at two to eight degrees Celsius for short intervals or frozen for longer storage. Stability studies focus on the acetylated terminus and the disulfide linkage because those features define the intact molecule. Common degradation routes include cysteine oxidation, deamidation of asparagine or glutamine side chains, and slow formation of higher-molecular-weight species.
=== Variants and subgroups === Regulators and clinical trials often use additional subgroups based on how active the disease is, even if there is no firm agreement on their definition. Examples are 'active MS', 'highly active MS' and 'rapidly evolving severe MS'. One definition of highly active MS is having an unchanged or increased number of relapses even after starting disease-modifying treatment. In addition, the term 'relapsing MS' is often used to denote people with relapsing-remitting MS as well as the subset of individuals with secondary progressive MS who still experience some relapses. The terms "benign MS" is sometimes used for people who have had MS for a long time (15 years or so) with few attacks and little disability. As people may still get worse, the term is discouraged. On the other hand, the term aggressive multiple sclerosis (previously known as "malignant multiple sclerosis") is used to describe people with MS having reached a significant level of disability in a short period. Atypical variants of MS have been described; these include tumefactive multiple sclerosis, Balo concentric sclerosis, and Marburg multiple sclerosis.
Other than fat, glucose is stored in most tissues, as an energy resource available within the tissue through glycogenesis which was usually being used to maintain blood glucose levels. Polysaccharides and glycans are made by the sequential addition of monosaccharides by glycosyltransferase from a reactive sugar-phosphate donor such as uridine diphosphate glucose (UDP-Glc) to an acceptor hydroxyl group on the growing polysaccharide. As any of the hydroxyl groups on the ring of the substrate can be acceptors, the polysaccharides produced can have straight or branched structures. The polysaccharides produced can have structural or metabolic functions themselves, or be transferred to lipids and proteins by the enzymes oligosaccharyltransferases.
== History == Multiple epiphyseal dysplasia was described separately by Seved Ribbing and Harold Arthur Thomas Fairbank in the 1930s. In 1994, Ralph Oehlmann's group mapped MED to the peri-centromeric region of chromosome 19, using genetic linkage analysis. Michael Briggs' group mapped PSACH to the same area. COMP gene was firstly linked to MED and PSACH in 1995. In 1995, the group led by Knowlton did a "high-resolution genetic and physical mapping of multiple epiphyseal dysplasia and pseudoachondroplasia mutations at chromosome 19p13.1-p12." Research on COMP led to mouse models of the pathology of MED. In 2002, Svensson's group generated a COMP-null mouse to study the COMP protein in vivo. These mice showed no anatomical, histological, or even ultrastructural abnormalities and none of the clinical signs of PSACH or MED. Lack of COMP was not compensated for by any other protein in the thrombospondin family. This study confirmed that the disease is not caused by reduced expression of COMP. In 2007, Piròg-Garcia's group generated another mouse model carrying a mutation previously found in a human patient. With this new model, they were able to demonstrate that reduced cell proliferation and increased apoptosis are significant pathological mechanisms involved in MED and PSACH. In 2010, this mouse model allowed a new insight into myopathy and tendinopathy, which are often associated with PSACH and MED. These patients show increased skeletal muscle stress, as indicated by the increase in myofibers with central nuclei.
Sources: en.wikipedia.org
In some cases, even marine taxa that had acquired spongy bone can revert to thicker, compact bones if they become adapted to live in shallow water, or in hypersaline (denser) water. Many animals, particularly herbivores, practice osteophagy—the eating of bones. This is presumably carried out in order to replenish lacking phosphate. Many bone diseases that affect humans also affect other vertebrates—an example of one disorder is skeletal fluorosis.
==== Fibroblasts ==== The scarring is created by fibroblast proliferation, a process that begins with a reaction to the clot. To mend the damage, fibroblasts slowly form the collagen scar. The fibroblast proliferation is circular and cyclically, the fibroblast proliferation lays down thick, whitish collagen inside the provisional and collagen matrix, resulting in the abundant production of packed collagen on the fibers giving scars their uneven texture. Over time, the fibroblasts continue to crawl around the matrix, adjusting more fibers and, in the process, the scarring settles and becomes stiff. This fibroblast proliferation also contracts the tissue. In unwounded tissue, these fibers are not overexpressed with thick collagen and do not contract. EPF and ENF fibroblasts have been genetically traced with the Engrailed-1 genetic marker. EPFs are the primary contributors to all fibrotic outcomes after wounding. ENFs do not contribute to fibrotic outcomes.
=== Heritable connective tissue disorders === Hereditary connective tissue disorders are a diverse set of broad, single-gene disorders that impact one or more of the main components of connective tissues, such as ground substance (glycosaminoglycans), collagen, or elastin. Many result in anomalies of the skeleton and joints, which can substantially impair normal growth and development. In contrast to acquired connective tissue diseases, these conditions are uncommon.
Sources: en.wikipedia.org
=== 2017 === The "Duty to Warn" movement was founded by medical professionals concerned about Trump's cognitive health in his first year in office. In 2016 and 2017, a number of psychiatrists and clinical psychologists faced criticism for violating the Goldwater rule; despite having never examined him, they maintained that Donald Trump displayed "an assortment of personality problems, including grandiosity, a lack of empathy, and 'malignant narcissism'", and that he had a "dangerous mental illness". In 2017, psychologist John Gartner collected more than 41,000 signatures of mental health professionals on a petition, directed to then-Senate Minority Leader Chuck Schumer. The petition asserted that Trump suffered from a serious mental illness and was "psychologically incapable of competently discharging the duties" of the presidency. Gartner asserted that Trump's mental handicaps are a mix of narcissism, paranoia, sociopathy, and sadism. In February 2017, psychiatrist Allen Frances wrote a letter to the editor of The New York Times regarding Trump and narcissistic personality disorder. Frances said, "I wrote the criteria that define this disorder, and Mr. Trump doesn't meet them." According to the American Psychiatric Association, "saying that a person does not have an illness is also a professional opinion." On April 14, 2017, Representatives Jamie Raskin and Earl Blumenauer introduced the Oversight Commission on Presidential Capacity Act.
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Some enzymes do not need additional components to show full activity. Others require non-protein molecules called cofactors to be bound for activity. Cofactors can be either inorganic (e.g., metal ions and iron–sulfur clusters) or organic compounds (e.g., flavin and heme). These cofactors serve many purposes; for instance, metal ions can help in stabilizing nucleophilic species within the active site. Organic cofactors can be either coenzymes, which are released from the enzyme's active site during the reaction, or prosthetic groups, which are tightly bound to an enzyme. Organic prosthetic groups can be covalently bound (e.g., biotin in enzymes such as pyruvate carboxylase). An example of an enzyme that contains a cofactor is carbonic anhydrase, which uses a zinc cofactor bound as part of its active site. These tightly bound ions or molecules are usually found in the active site and are involved in catalysis. For example, flavin and heme cofactors are often involved in redox reactions. Enzymes that require a cofactor but do not have one bound are called apoenzymes or apoproteins. An enzyme together with the cofactor(s) required for activity is called a holoenzyme (or haloenzyme). The term holoenzyme can also be applied to enzymes that contain multiple protein subunits, such as the DNA polymerases; here the holoenzyme is the complete complex containing all the subunits needed for activity.
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.
Lyophilized powder is normally kept at minus twenty degrees Celsius or below, in a sealed container, desiccated and away from light. Reconstituted solutions are less stable and are usually refrigerated and used quickly. Repeated temperature cycling should be avoided.