Everything below concerns freeze-dried powder. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-03-23. 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.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography together with mass spectrometry. The chromatogram provides a purity estimate as a percentage of total peak area, while the mass spectrum confirms that the observed mass matches the expected value. Amino acid analysis or tandem mass spectrometry sequencing can provide additional confirmation. Reported purity figures depend on the column, gradient, and detection wavelength, so values from different laboratories are not directly comparable without method details.
Lyophilised peptide is normally reconstituted with sterile water or a neutral buffer shortly before use. Because repeated freeze-thaw cycles can degrade the material, dividing a reconstituted solution into single-use aliquots is a common practice. Working solutions are usually kept cold and protected from light. The exact shelf life depends on concentration, buffer composition, and handling, so it is often determined empirically rather than assumed.
| 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 |
Material sold under this label typically arrives as a freeze-dried powder in a sealed vial with a certificate of analysis. Such certificates usually report reversed-phase chromatography purity plus a mass confirmation, and stated purities commonly sit between 95 and 99 percent. Counter-ion identity, residual trifluoroacetate, water content, and peptide net weight are separate specifications that a certificate may or may not include. A purity figure alone does not establish sequence identity, so independent mass verification remains the practical check.
The designation TB-500 circulates in laboratory and catalog contexts without a single agreed definition. Most product listings apply it to an N-terminally acetylated seven-residue fragment of thymosin beta-4, while other listings attach the same label to the full 43-residue protein. Because the term is commercial rather than systematic, two entries bearing identical names may describe different molecules. Any documentation should therefore state which sequence a given sample is claimed to contain.
Storage recommendations center on keeping the dry powder cold, dry, and dark. A freezer at -20 degrees Celsius or below is conventional, and desiccant is often included to limit moisture uptake. Once dissolved, the peptide is less stable, and solutions are typically kept frozen and thawed only once. Repeated freeze-thaw cycles are a common source of losses because they promote aggregation and adsorption to container surfaces. Working aliquots are therefore prepared in advance, and glass or low-binding plastic is usually preferred over ordinary laboratory plastic.
Identity and purity are assessed with a small set of standard techniques. Reverse-phase high-performance liquid chromatography gives a purity estimate from peak area, usually recorded at 214 or 220 nanometers, where the peptide bond absorbs. Mass spectrometry confirms the expected molecular mass and can reveal truncated or oxidized species. Amino acid analysis or tandem mass spectrometry sequencing can verify the sequence itself. Additional quality attributes include water content, residual trifluoroacetic acid carried over from purification, and endotoxin where the material is intended for biological work.
The compound is most often distributed as a lyophilized powder, appearing white to off-white and forming a loose cake or fluffy solid. It is hygroscopic to some degree, so brief exposure to humid air can add water weight and complicate weighing. The peptide dissolves readily in water and in neutral aqueous buffers, and aqueous solubility is generally described as high, well above the concentrations used in typical assays. Some polar organic solvents are also usable, which matters when a concentrated stock is prepared before dilution into buffer.
TB-500 is a synthetic peptide whose sequence corresponds to a short fragment near the N-terminus of thymosin beta-4, a small protein present in most mammalian cells. The fragment is commonly cited as containing the actin-binding region of the parent molecule, which is why it appears in laboratory work on cell migration and tissue repair. Suppliers distribute it as a lyophilised powder intended for research use. Its identity is defined by amino acid sequence and by the presence of an acetyl group on the N-terminal residue.
Full-length thymosin beta-4 consists of roughly forty-three amino acids and ranks among the more abundant small proteins in the cytoplasm. The fragment is much shorter, so it cannot reproduce every function attributed to the intact molecule. In cell culture, short actin-binding motifs can interfere with filament dynamics and cell movement, but such observations come from controlled experiments rather than from whole-animal work. Whether a truncated fragment produces the same effects as the parent protein remains an open question.
=== Little Projects === In 2011, Little founded Little Projects, a residential and commercial property projects group. His business philosophy is to provide a 'one-stop shop' approach, where clients deal with the one entity for all their real estate requirements encompassing buying, selling and comprehensive property management. To this end Little has purchased a range of complementary businesses including three LJ Hooker real estate franchises. He has a large number of projects underway in Melbourne with a value of over $1 billion.
== Interleukin antagonists == Interleukins are a cytokine that play a major role in the immune system. IL-12 and IL-23 help with the activation and differentiation of natural killer cells and CD4+ T lymphocyte, both of which contribute to inflammation. Interleukin antagonists, the most recent class of biologics available for use in IBD, inhibit the action of IL-12 and IL-23 by binding to the p40 protein subunit that is found on both of these cytokines.
(1936), Recollections and Reflections, London: G. Bell & Sons, Ltd. Republished as digital edition, Cambridge: University Press, 2011 (Cambridge Library Collection series). Thomson, George Paget. (1964) J.J. Thomson: Discoverer of the Electron. Great Britain: Thomas Nelson & Sons, Ltd. Davis, Eward Arthur & Falconer, Isobel (1997), J.J. Thomson and the Discovery of the Electron. ISBN 978-0-7484-0696-8 Falconer, Isobel (1988) "J.J. Thomson's Work on Positive Rays, 1906–1914" Historical Studies in the Physical and Biological Sciences 18(2) 265–310 Falconer, Isobel (2001) "Corpuscles to Electrons" in J Buchwald and A Warwick (eds) Histories of the Electron, Cambridge, Mass: MIT Press, pp. 77–100. Navarro, Jaume (2005). "J. J. Thomson on the Nature of Matter: Corpuscles and the Continuum". Centaurus. 47 (4): 259–282. Bibcode:2005Cent...47..259N. doi:10.1111/j.1600-0498.2005.00028.x. Downard, Kevin M. (2009). "J. J. Thomson goes to America". Journal of the American Society for Mass Spectrometry. 20 (11): 1964–1973. Bibcode:2009JASMS..20.1964D. doi:10.1016/j.jasms.2009.07.008. PMID 19734055. S2CID 34371775.
== Adverse effects == The most common side effects (seen in more than 1% of patients) are upper abdominal (belly) pain, diarrhoea, dry mouth, and nausea or vomiting. Allergic reactions of the skin like itching, rashes, hives and angiooedema are rare. The same is true for anaphylactic shock and convulsions.
β-Naltrexamine, or 6β-naltrexamine, is an opioid receptor antagonist related to naltrexol and naltrexone. It has served as a parent pharmacophore for irreversible antagonists of the μ-opioid receptor (MOR) such as β-chlornaltrexamine (β-CNA) and β-funaltrexamine (β-FNA). Naltrexamine itself is a neutral antagonist of the MOR and the δ-opioid receptor (DOR) with similarly high affinity for both receptors.
Sources: en.wikipedia.org
In March 2001, Taco Bell announced a promotion to coincide with the re-entry of the Mir space station. They towed a large target out into the Pacific Ocean, announcing that if the target was hit by a falling piece of Mir, every person in the United States would be entitled to a free Taco Bell taco. The company bought a sizable insurance policy for this gamble. No piece of the station struck the target. In 2004, a local Taco Bell franchisee bought the naming rights to the Boise State Pavilion in Boise, Idaho, and renamed the stadium Taco Bell Arena. Also, in 2004, Mountain Dew offered Taco Bell stores the exclusive right to carry Mountain Dew Baja Blast, a tropical lime flavor of the popular soft drink. In 2005, Taco Bell released the menu item called the Crunchwrap Supreme as a limited-time offer. Due to its success, the Crunchwrap Supreme was made a permanent menu offering in 2006. In 2007, Taco Bell first offered the "Steal a Base, Steal a Taco" promotion—if any player from either team stole a base in the World Series, the company would give away free tacos to everyone in the United States in a campaign similar to the Mir promotion, albeit with a much higher likelihood of being realized. After Jacoby Ellsbury of the Boston Red Sox stole a base in Game 2, the company made good on the promotion on October 30, 2007. The promotion has subsequently been offered in multiple World Series.
This list of former RAF stations includes most of the stations, airfields and administrative headquarters previously used by the Royal Air Force. They are listed under any former county or country name which was appropriate for the duration of operation. During 1991, the RAF had several Military Emergency Diversion Aerodrome (MEDA) airfields: RAF Kinloss, Leeming, Valley, Waddington, Wattisham & Lyneham ended their role from 1 March 1991, leaving Brize Norton, Manston, Leuchars and St Mawgan with the role.
The Lund/LBNL Nuclear Data Search – Contains tabulated information on radioactive decay types and energies. Nomenclature of nuclear chemistry Archived 12 February 2015 at the Wayback Machine Specific activity and related topics. The Live Chart of Nuclides – IAEA Interactive Chart of Nuclides Archived 10 October 2018 at the Wayback Machine Health Physics Society Public Education Website Beach, Chandler B., ed. (1914). "Becquerel Rays" . The New Student's Reference Work . Chicago: F. E. Compton and Co. Annotated bibliography for radioactivity from the Alsos Digital Library for Nuclear Issues Archived 7 October 2010 at the Wayback Machine "Henri Becquerel: The Discovery of Radioactivity", Becquerel's 1896 articles online and analyzed on BibNum [click 'à télécharger' for English version]. "Radioactive change", Rutherford & Soddy article (1903), online and analyzed on Bibnum [click 'à télécharger' for English version]
=== Skeleton === Sex hormones play an important role in bone growth and maintenance. The effects of hormone therapy on bone health are not fully understood, and may depend on whether hormone therapy is started before or after puberty. Bone density continue to grow and change over time. Significant changes to bone structure have been observed, and transgender women have statistically poorer bone health even before beginning the transition process, possibly due to a lack of physical exercise or other risk factors such as low vitamin D, eating disorders, and substance abuse. Approximately 14% of transgender women suffer from osteoporosis. Transgender women below the age of 50 show increased fracture risk compared to age-matched cisgender women, equal to the risk to cisgender men of equivalent age. Transgender women above the age of 50 have a similar fracture risk to post-menopausal women — higher than that of age-matched cis men. In both cases, trans women's fracture patterns follow that of cis women, suffering long-term stress fractures concentrated in the hip, spine, and arms, typical of chronic low bone mineral density, rather than the fracture patterns typical of external injury suffered by cis men. Current clinical guidelines are for bone health to be monitored regularly throughout the transition process, particularly if risk factors are present. Transgender individuals are encouraged to ingest at least 1g of Calcium and 1000 IU of Vitamin D daily, engage regularly in weight-bearing physical activity, and reduce alcohol and smoking consumption.
=== Exhibition in June 1933 in Paris === General Gouraud granted his patronage for an exhibition in the function hall of the town hall of the 13th district of Paris. The exhibition, Visions féeriques d’Orient (Fantasy Perspectives of the East), grouped together some 172 plates: 80 plates from the Basilique de Sainte-Sophie de Constantinople (Basilica of Hagia Sophia of Constantinople) and 92 plates from L'Art Islamique en Orient (Islamic Art in the East). Raymond’s name was not mentioned on the cover of the exhibition brochure.
Sources: en.wikipedia.org
== Early life and education == Leena Maria Hämäläinen (later Ala-Kokko) was born on 21 July 1961 in Oulu, Finland. She graduated from high school at Oulun Lyseon lukio in 1980. She continued her studies at the University of Oulu, from which she obtained her licentiate in medicine in 1986, before gaining her PhD in medicine the following year. In her thesis, Ala-Kokko studied the overproduction of collagen in the skin and liver. Ala-Kokko gained research experience in professor Kari Kivirikko's collagen research group.
McArdle disease (GSD-V) is inherited in an autosomal recessive manner. If both parents are carriers (not having the disease, but each parent having one copy of the mutated allele), then each child of the couple will have a 25% chance of being affected (having McArdle disease), a 50% chance of being a carrier, and a 25% chance of being unaffected (neither a carrier nor diseased). Two autosomal recessive forms of this disease occur, childhood-onset and adult-onset. The gene for myophosphorylase, PYGM (the muscle-type of the glycogen phosphorylase gene), is located on chromosome 11q13. According to the most recent publications, 95 different mutations have been reported. The forms of the mutations may vary between ethnic groups. For example, the R50X (Arg50Stop) mutation (previously referred to as R49X) is most common in North America and Western Europe, and the Y84X mutation is most common among central Europeans. The exact method of protein disruption has been elucidated in certain mutations. For example, R138W is known to disrupt to pyridoxal phosphate binding site. In 2006, another mutation (c.13_14delCT) was discovered which may contribute to increased symptoms in addition to the common Arg50Stop mutation.
== External links == Jewish State.com Zionism, News, Links Israeli Jewish scene from ynetnews Israel as a Jewish state from the Jerusalem Center for Public Affairs 'Israel a Jewish state first', says former High Court Justice Dalia Dorner
According to the nomenclature recommended by IUPAC, salts are named according to their composition, not their structure. In the most simple case of a binary salt with no possible ambiguity about the charges and thus the stoichiometry, the common name is written using two words. The name of the cation (the unmodified element name for monatomic cations) comes first, followed by the name of the anion. For example, MgCl2 is named magnesium chloride, and Na2SO4 is named sodium sulfate (SO2−4, sulfate, is an example of a polyatomic ion). To obtain the empirical formula from these names, the stoichiometry can be deduced from the charges on the ions, and the requirement of overall charge neutrality. If there are multiple different cations and/or anions, multiplicative prefixes (di-, tri-, tetra-, ...) are often required to indicate the relative compositions, and cations then anions are listed in alphabetical order. For example, KMgCl3 is named magnesium potassium trichloride to distinguish it from K2MgCl4, magnesium dipotassium tetrachloride (note that in both the empirical formula and the written name, the cations appear in alphabetical order, but the order varies between them because the symbol for potassium is K). When one of the ions already has a multiplicative prefix within its name, the alternate multiplicative prefixes (bis-, tris-, tetrakis-, ...) are used. For example, Ba(BrF4)2 is named barium bis(tetrafluoridobromate).
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.
The lyophilised powder is typically held at -20 C or lower in a dry, dark place. Reconstituted solutions are aliquoted and frozen to avoid repeated freeze-thaw cycles.