thymosin beta-4 is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2025-09-21. Where a claim depends on a specific study, the study is described rather than over-claimed.
Several names appear in scientific and commercial contexts for this peptide. The label TB-500 is informal and does not follow standard biochemical nomenclature. Research articles more often describe the compound as a thymosin beta-4 fragment, Tβ4 fragment, or by its sequence Ac-LKKTETQ. Confusing TB-500 with full-length thymosin beta-4 can lead to incorrect assumptions about activity because the fragment lacks the remaining residues of the parent protein. The relationship between fragment and parent protein remains an active area of study.
Regulatory status differs by country, but TB-500 is not an approved pharmaceutical in major jurisdictions. It is commonly sold as a research chemical for laboratory use, which places responsibility for identity and purity on the supplier and the laboratory. Published human data are limited, and most reports involve preclinical models or cell culture. Questions about whether the fragment mimics all actions of thymosin beta-4, and under which conditions, remain open. Independent verification of any material is therefore a practical requirement in research settings.
TB-500 is a research peptide whose sequence matches residues 17 to 23 of thymosin beta-4, a 43-residue protein present in most mammalian cells. The chain is seven amino acids long, written as LKKTETQ, and is normally supplied with an acetyl group on the N-terminus. Suppliers list it as a lyophilised powder under the code name TB-500, and the same sequence appears elsewhere in catalogues as the thymosin beta-4 actin-binding fragment. The label is commercial rather than systematic, so no single authority fixes exactly what TB-500 denotes.
Thymosin beta-4 was isolated from calf thymus in the early 1980s and later characterised as an abundant intracellular actin-sequestering protein. Interest in short synthetic fragments grew once the actin-binding motif had been mapped to the middle of the sequence. TB-500 came out of that line of work as a truncated analogue rather than a natural isolate, and it is now sold mainly to laboratories. Published studies on the fragment have been largely in vitro or in animal models, and controlled human trials remain sparse, so claims about effects in people rest on extrapolation.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H68N10O14 | Calculated for the acetylated heptapeptide |
| Molecular weight | ~889 Da | Monoisotopic mass approximately 889.0 Da |
| Amino acid sequence | Ac-LKKTETQ | N-terminal acetylated seven-residue peptide |
| Appearance | White to off-white powder | Typically supplied as a lyophilized solid |
| Solubility class | Water-soluble | Peptides of this size generally dissolve in aqueous media |
Dry powder is commonly held at minus twenty degrees Celsius, with some suppliers recommending lower temperatures for long-term archival storage. Once dissolved, solutions are typically kept cold and protected from light, since aqueous peptide solutions can lose integrity through hydrolysis or oxidation over time. Stability data specific to this fragment are limited in the public literature, and much of the guidance comes from general peptide handling practice rather than from controlled degradation studies. Users therefore treat stated shelf lives as approximate rather than fixed.
Identity and purity are normally assessed with reversed-phase high-performance liquid chromatography, paired with mass spectrometry to confirm molecular mass. A certificate of analysis reports a purity percentage, usually derived from chromatographic peak area, but that figure does not by itself prove a correct sequence or the absence of counterions. Independent verification may include amino acid analysis or peptide mapping. Batch-to-batch variation is a documented concern in the research chemical market, and the gap between a quoted purity value and actual peptide content can be substantial when the material is a salt or retains residual water.
Lyophilized peptide arrives as a dry cake that should stay sealed until use. Reconstitution is generally performed with sterile water or a buffered solution, and the resulting liquid should be handled gently to limit mechanical stress. Repeated freeze-thaw cycles are widely described as harmful to short peptides, so dividing a reconstituted batch into single-use portions is a common practice. Laboratories also record the solvent, concentration, and date of preparation on the vial label to keep later measurements traceable.
TB-500 is a catalogue name applied to a synthetic peptide related to thymosin beta-4, an actin-binding protein found in most mammalian cells. Suppliers do not use the label consistently: some describe it as the full 43-residue protein, others as a short fragment from the actin-binding region, and others as a related tetrapeptide. Because the name is commercial rather than chemical, two products sold under it may not contain the same molecule. This naming ambiguity is the first point to check in any description of the material.
The most frequently cited identity is a seven-residue fragment with the sequence LKKTETQ, taken from the actin-binding domain of the parent protein. A separate molecule, N-acetyl-seryl-aspartyl-lysyl-proline, often shortened to Ac-SDKP, derives from the same protein's N-terminal region and appears in overlapping literature. Reported molecular masses therefore differ between sources, and a mass value on its own does not establish which fragment is present. Confirmation requires a defined sequence rather than a single number.
Research interest in thymosin beta-4 fragments centres on actin sequestration, cell migration and tissue repair models. Most published work uses cultured cells or animal wound and cardiac preparations, and findings are generally described as preliminary. No fragment of this protein has been approved as a therapeutic product by major regulators. Reviews of the field note inconsistent dosing, delivery routes and outcome measures across studies, which complicates direct comparison. The material is best understood as a laboratory reagent with an active but unresolved research literature.
Thymosin beta-4 contains 43 amino acids and has a reported molecular mass near 4963 Da. The short fragment most often associated with the TB-500 label, an acetylated chain beginning LKKTETQ, has a reported mass near 889 Da, so the two are easily separated in analytical work. Mass spectrometry and amino acid analysis can confirm which material is present in a given sample. Statements treating TB-500 and thymosin beta-4 as interchangeable are therefore imprecise, even though the two appear together in much of the same literature.
Interest in the compound comes largely from studies of the parent protein, which participates in actin sequestration, cell migration and tissue repair processes. Whether a short fragment reproduces those activities is a separate question that remains open in the published record. Many summaries describe mechanisms by analogy to thymosin beta-4 rather than from direct measurements on the fragment. Claims about activity should be treated as provisional unless a cited study specifies the exact peptide, its purity and the assay used.
TB-500 is a laboratory label applied to a short synthetic peptide that is widely described as a fragment of thymosin beta-4, an actin-binding protein present in most mammalian cells. Suppliers and review articles usually present TB-500 as the N-terminal region of that protein, but the exact sequence attached to the name is not consistent across sources. Some product descriptions list a seven-residue chain; others use the label loosely for the parent protein itself. Because of that variation, any technical discussion of TB-500 needs to state which sequence is meant.
Muscle cells (myocytes) form the active contractile tissue of the body. Muscle tissue functions to produce force and cause motion, either locomotion or movement within internal organs. Muscle is formed of contractile filaments and is separated into three main types; smooth muscle, skeletal muscle and cardiac muscle. Smooth muscle has no striations when examined microscopically. It contracts slowly but maintains contractility over a wide range of stretch lengths. It is found in such organs as sea anemone tentacles and the body wall of sea cucumbers. Skeletal muscle contracts rapidly but has a limited range of extension. It is found in the movement of appendages and jaws. Obliquely striated muscle is intermediate between the other two. The filaments are staggered and this is the type of muscle found in earthworms that can extend slowly or make rapid contractions. In higher animals striated muscles occur in bundles attached to bone to provide movement and are often arranged in antagonistic sets. Smooth muscle is found in the walls of the uterus, bladder, intestines, stomach, oesophagus, respiratory airways, and blood vessels. Cardiac muscle is found only in the heart, allowing it to contract and pump blood round the body.
==== Cognitive behavioral therapy ==== Cognitive behavioral therapy (CBT) is useful in adolescents and adults with anorexia nervosa. One of the most known psychotherapy in the field is CBT-E, an enhanced cognitive-behavior therapy specifically focus to eating disorder psychopathology. Acceptance and commitment therapy is a third-wave cognitive-behavioral therapy which has shown promise in the treatment of AN. Cognitive remediation therapy (CRT) is also used in treating anorexia nervosa. Schema-Focused Therapy (a form of CBT) was developed by Dr. Jeffrey Young and is effective in helping patients identify origins and triggers for disordered eating.
In 1948, Lloyd Valberg participated in the 1948 Summer Olympics in London, which made him the first Singaporean to participate in the Olympic Games. The development of private sports and recreation clubs began in the 19th century colonial Singapore, with clubs founded during this time including the Cricket Club, the Singapore Recreation Club, the Singapore Swimming Club, and the Hollandse Club. Weightlifter Tan Howe Liang was Singapore's first Olympic medalist, winning a silver at the 1960 Rome Games. Singapore hosted the inaugural 2010 Summer Youth Olympics, in which 3,600 athletes from 204 nations competed in 26 sports. Indoor and water sports are some of the most popular sports in Singapore. At the 2016 Rio Olympics, Joseph Schooling won Singapore's first Olympic gold medal, claiming the 100-metre butterfly in a new Olympic record time of 50.39 seconds. Singapore sailors have had success on the international stage, with their Optimist team being considered among the best in the world. Despite its size, the country has dominated swim meets in the Southeast Asia Games. Its men's water polo team won the SEA Games gold medal for the 27th time in 2017, continuing Singapore sport's longest winning streak. At the 2024 Paris Olympics, Max Maeder won Singapore's first Olympic medal in sailing, achieving bronze at the Men's Formula Kite on National Day. At 17, he was also Singapore's youngest Olympic medalist. Singapore's women's table tennis team were silver medalists at the 2008 Beijing Olympics.
Sources: en.wikipedia.org
shall be loyal to the Union and its citizens; shall be a citizen of Myanmar who was born of both parents who were born in the territory under the jurisdiction of the Union and being Myanmar Nationals; shall be an elected person who has attained at least the age of 45; shall be well acquainted with the affairs of the Union such as political, administrative, economic and military; shall be a person who has resided continuously in the Union for at least 20 years up to the time of his election as President(Proviso: An official period of stay in a foreign country with the permission of the Union shall be counted as a residing period in the Union) shall he himself, one of the parents, the spouse, one of the legitimate children or their spouses not owe allegiance to a foreign power, not be subject of a foreign power or citizen of a foreign country. They shall not be persons entitled to enjoy the rights and privileges of a subject of a foreign government or citizen of a foreign country; shall possess prescribed qualifications of the President, in addition to qualifications prescribed to stand for election to the Hluttaw. Moreover, upon taking oath in office, the president is constitutionally forbidden from taking part in any political party activities (Chapter III, 64).
Datasets for Ethiopia and Zimbabwe reported undernutrition rates between 1.5 and 2 times higher in men than in women; however, in India and Pakistan, datasets rates of undernutrition were 1.5–2 times higher in women than in men. Intra-country variation also occurs, with frequent high gaps between regional undernutrition rates. Gender inequality in nutrition in some countries such as India is present in all stages of life. Studies on nutrition concerning gender bias within households look at patterns of food allocation, and one study from 2003 suggested that women often receive a lower share of food requirements than men. Gender discrimination, gender roles, and social norms affecting women can lead to early marriage and childbearing, close birth spacing, and undernutrition, all of which contribute to malnourished mothers. Within the household, there may be differences in levels of malnutrition between men and women, and these differences have been shown to vary significantly from one region to another, with problem areas showing relative deprivation of women. Samples of 1000 women in India in 2008 demonstrated that malnutrition in women is associated with poverty, lack of development and awareness, and illiteracy. The same study showed that gender discrimination in households can prevent a woman's access to sufficient food and healthcare. How socialization affects the health of women in Bangladesh, Najma Rivzi explains in an article about a research program on this topic.
It was only natural for those who wished to abolish families to include in their incendiary program the destruction of records that established the genealogies of all families—certain genealogies of the people, the bourgeoisie, and the nobility. [...] They needed to burn the proof of their ancestors' marriages, their parents', their own, and their children's. They no longer wanted marriages, so what did the registers of old Parisian parishes and municipalities matter to them? These documents, which for each family composed its history, were just ashes to be scattered to the wind. They knew that the records documenting their births, those of their wives, children, and grandparents would be lost. Yet they did not hesitate, despite realizing these births would remain uncertain and unproven in the future. What all sensible people living in society respect was reduced to nothing more than ashes cast to the wind. [...] If I foresaw revolutions, if I thought one might see terror return, I did not anticipate that innocent collections of documents—where the poor, commoners, artists, and craftsmen stood side by side with the rich, nobles, partisans, ministers, and princes—would become targets." In 1847, A. Taillandier published a list of the starting dates of parish registers in several cities, distinguishing births (baptisms), marriages, and deaths (burials). In the section on Paris, after transcribing the oldest records verbatim, he provided a list of parishes.
=== 1960s === In November 30, 1960, Grace announced a multi-million dollar expansion of its polymer chemicals division. In December 1969, Grace sold Grace Shipping Company to Prudential Lines for $445 million.
Sources: en.wikipedia.org
TB-500 is a synthetic heptapeptide corresponding to a fragment of thymosin beta-4. It is used in laboratory research and is not an approved drug.
No. Thymosin beta-4 is a 43-amino-acid protein, while TB-500 represents only a short N-terminal segment. The two should not be treated as interchangeable in experimental design.
It is often called a thymosin beta-4 fragment, Tβ4 fragment, or Ac-LKKTETQ. The name TB-500 is mainly a commercial or catalog label rather than a formal chemical name.
No. Thymosin beta-4 is a 43-residue protein, while TB-500 matches only residues 17 to 23 of that chain. The two are related but differ in size, and a method that identifies one does not automatically identify the other.