The short version of deamidation fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
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.
The peptide occurs naturally in thymic tissue and has been detected in serum and other biological fluids. Reported concentrations are low, and reliable measurement generally requires immunoassay or mass spectrometry with an enrichment step. It is released from a larger precursor, prothymosin alpha, by proteolytic cleavage, although the enzymes involved are not fully characterized. Whether circulating levels reflect thymic output specifically remains an open question.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C129H215N33O55 | Calculated for the acetylated 28-residue peptide |
| Appearance | White to off-white powder | Lyophilized solid recovered from aqueous buffer |
| Solubility | Freely soluble in water | Typically dissolved in water or buffer before use |
| Typical storage | -20 C or below, desiccated | Protect from light and avoid repeated freeze-thaw cycles |
| Identity testing | Reverse-phase HPLC with mass spectrometry | Retention time and measured mass confirm the sequence |
Reverse-phase high-performance liquid chromatography is the standard technique for assessing purity and concentration, because the peptide's hydrophobicity allows clean separation from related impurities. Mass spectrometry confirms molecular identity and detects sequence errors or truncations. Amino acid analysis and peptide mapping supply additional structural confirmation when required. Chromatographic purity values reported on certificates of analysis describe the proportion of the main peak and do not by themselves establish biological activity.
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.
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。
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。
Several factors accelerate degradation: alkaline pH, elevated temperature, exposure to oxidants, and the presence of residual moisture. Deamidation of asparagine residues and oxidation of methionine are the most commonly reported degradation routes. Because the peptide lacks disulfide bonds, it does not undergo the thiol-related aggregation seen in some other biologics, but physical aggregation can still occur at high concentration. Stability data are product-specific, and extrapolating shelf life between formulations is not reliable.
Lyophilized thymosin alpha-1 is generally stored at or below minus twenty degrees Celsius, protected from moisture and light. Short-term handling at ambient temperature is possible for dry powder, but reconstituted solutions degrade faster and are usually kept at two to eight degrees Celsius with a defined expiry of days rather than weeks. Repeated freeze-thaw cycles should be avoided because they promote aggregation and loss of potency. Exact limits depend on the formulation and should follow the supplier's documentation.
Identity and purity are normally assessed by reversed-phase high-performance liquid chromatography, which separates the peptide from related impurities and truncation products. Mass spectrometry confirms molecular mass and detects modifications such as deamidation or oxidation. Amino acid analysis and peptide mapping provide additional sequence-level confirmation. For research material, a certificate of analysis typically reports these results together with water content and counter-ion identity, since the lyophilized powder is often supplied as an acetate or trifluoroacetate salt.
Overall evidence quality varies considerably. A large share of published reports come from single centers, rely on surrogate immunological markers, or lack adequate control groups. Systematic reviews have highlighted this heterogeneity as a barrier to pooling results. Open questions include which patients, if any, might benefit, what treatment duration is appropriate, and whether any effect is independent of standard care. The peptide is often described as an immune modulator rather than a therapy for one disease, which complicates confirmatory trial design.
Thymosin alpha 1 was identified in 1977 as a component of thymosin fraction 5, a heterogeneous preparation used in early studies of thymic function. Investigators purified the active material and determined its amino acid sequence, which enabled chemical synthesis. Work in the following decades concentrated on T-cell maturation and immune reconstitution in animals and small human cohorts. Early preparations varied in composition, so results from that period are difficult to compare with studies using defined synthetic peptide.
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Findings across trials are mixed; some report changes in selected immune markers, while others find no clear clinical benefit. Many studies are small and define outcomes differently, which limits comparison. Regulatory approval is confined to a few countries, and the compound is not an approved drug in the United States or most of Europe.
== Medical uses == Lurbinectedin is indicated for the treatment of adults with metastatic small cell lung cancer with disease progression on or after platinum-based chemotherapy. In October 2025, the indication for lurbinectedin was expanded to include using lurbinectedin in combination with atezolizumab or in combination with atezolizumab/hyaluronidase for the maintenance treatment of adults with extensive-stage small cell lung cancer whose disease has not progressed after first-line induction therapy with atezolizumab or atezolizumab and hyaluronidase, carboplatin, and etoposide.
== See also == Chirality (electromagnetism) Chirality (mathematics) Chirality (physics) Enantiopure drug Enantioselective synthesis Handedness Orientation (vector space) Pfeiffer effect Pseudochirality Stereochemistry for overview of stereochemistry in general Stereoisomerism Supramolecular chirality
Pure boron is a shiny, silver-grey crystalline solid. It is less dense than aluminium (2.34 vs. 2.70 g/cm3), and is hard and brittle. It is barely reactive under normal conditions, except for attack by fluorine, and has a melting point of 2076 °C (cf. steel ~1370 °C). Boron is a semiconductor; its room temperature electrical conductivity is 1.5 × 10−6 S•cm−1 (about 200 times less than that of tap water) and it has a band gap of about 1.56 eV. Mendeleev commented that, "Boron appears in a free state in several forms which are intermediate between the metals and the nonmmetals." The structural chemistry of boron is dominated by its small atomic size, and relatively high ionization energy. With only three valence electrons per boron atom, simple covalent bonding cannot fulfil the octet rule. Metallic bonding is the usual result among the heavier congeners of boron but this generally requires low ionization energies. Instead, because of its small size and high ionization energies, the basic structural unit of boron (and nearly all of its allotropes) is the icosahedral B12 cluster. Of the 36 electrons associated with 12 boron atoms, 26 reside in 13 delocalized molecular orbitals; the other 10 electrons are used to form two- and three-centre covalent bonds between icosahedra. The same motif can be seen, as are deltahedral variants or fragments, in metal borides and hydride derivatives, and in some halides. The bonding in boron has been described as being characteristic of behaviour intermediate between metals and nonmetallic covalent network solids (such as diamond).
== Patents == This is a highly competitive area and a number of people claim patents in the field, most notably Alere (formerly Inverness Medical Innovations, now owned by Abbott) who own patents originally filed by Unipath. The US 6,485,982 patent, that has been litigated, expired in 2019. A number of other companies also hold patents in this arena. A group of competitors are challenging the validity of the patents. The original patent is apparently from 1988.
The method is a nonspecific assay- it is unable to differentiate between YTX and other sample components, including DSP toxins The method has economic and social issues with regards to testing on animals. The results produced are not very reproducible. The method has insufficient detection capabilities. The method, though, is quick and inexpensive. Due to these factors, the other, more recently developed, techniques are being preferred for analysis of YTX.
Sources: en.wikipedia.org
"During the first three days there was continuous torture. I was beaten with an aluminum rod and with cables. ? Then I was told to sign a statement with my hands tied behind my back, so I didn't even see the paper and I don't know what I signed."
Invasive garlic mustard, Alliaria petiolata, and its allelochemical benzyl isothiocyanate were shown to inhibit the growth of three species of EcM fungi grown on white pine seedlings. Changes in EcM communities can have drastic effects on nutrient uptake and community composition of native trees, with far-reaching ecological ramifications.
As an expansion pack for Half-Life, Blue Shift is a first-person shooter. The overall gameplay of Blue Shift does not significantly differ from that of Half-Life: players are required to navigate through the game's levels, fight hostile non-player characters and solve a variety of puzzles to advance. The game continues Half-Life's methods of an unbroken narrative. The player sees everything through the first-person perspective of the protagonist, and remains in control of the player character for almost all the game. Story events are conveyed through the use of scripted sequences rather than cut scenes. Progress through the game's world is continuous; although the game is divided up into chapters, the only significant pauses are when the game needs to load the next part of an environment. The player battles through the game alone, but is occasionally assisted by friendly non-player characters. Security guards and scientists will occasionally help the player in reaching new areas and convey relevant plot information. Blue Shift also includes a substantial section dedicated to keeping a major character in the story safe from enemy characters, and escorting him to a specific location. A selection of enemies from Half-Life populate the game, including alien creatures such as headcrabs and Vortigaunts. The player also encounters human opponents in the form of a detachment of US Marines who have been sent to eliminate the alien threat and silence any witnesses.
== External links == "Calcitonin Receptors". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. Archived from the original on 2016-03-03. Retrieved 2007-07-23. Calcitonin+receptors at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
== Ecological relevance == Numerous studies and published data comparing Microtox results with toxicity values for fish, crustaceans and algae have found a positive correlation. However, others have pointed out that the effect of luminosity on the survival of organisms is unknown. Concerns have also been expressed regarding the use of sediment extracts and not the sediment itself. It is possible that only water-soluble contaminants will be tested for, and therefore may not be representative of the full range of contaminants present in the sediment. Extracts may also remove contaminants that are not bioavailable. This could lead to an over or under estimation of contaminants and their biological effects.
Sources: en.wikipedia.org
=== Diagnosis and treatment === In current practice for dogs, B. canis is diagnosed using PCR, cultures, and serologic testing. The most standard test for B. canis is culture. These cultures are typically conducted on the host's blood, vaginal discharge, or semen. However, this method is not effective if the dog has been treated with antimicrobial drugs, as this will clear B. canis bacteria even if the disease has not resolved. Serology is used to evaluate the antibody response against Brucella spp. cell wall antigens, the downfall of this method is its lack of specificity. PCR testing has shown potential as a rapid test, however it is not readily available and is currently considered an experimental test. Currently, there are not commercially available vaccines for B. canis. Antimicrobial treatment and sterilization of the infected animals is considered an alternative to removing the animal. There have been reports of anti-Brucella vaccines (used for cattle and small ruminants), used along with previously mentioned methods but is not considered practical due to its risk of vaccine strain shedding in a domestic environment with current vaccines maintaining an amount of virulence for humans. Treatment for B. canis is very difficult to find and often very expensive. This is due to B. canis being a intracellular bacteria, meaning it replicates inside of host cells rather than outside of them. This makes it difficult for antibiotics to reach the bacteria.
The multiplex or Fellgett's advantage (named after Peter Fellgett). This arises from the fact that information from all wavelengths is collected simultaneously. It results in a higher signal-to-noise ratio for a given scan-time for observations limited by a fixed detector noise contribution (typically in the thermal infrared spectral region where a photodetector is limited by generation-recombination noise). For a spectrum with m resolution elements, this increase is equal to the square root of m. Alternatively, it allows a shorter scan-time for a given resolution. In practice multiple scans are often averaged, increasing the signal-to-noise ratio by the square root of the number of scans. The throughput or Jacquinot's advantage (named after Pierre Jacquinot). This results from the fact that in a dispersive instrument, the monochromator has entrance and exit slits which restrict the amount of light that passes through it. The interferometer throughput is determined only by the diameter of the collimated beam coming from the source. Although no slits are needed, FTIR spectrometers do require an aperture to restrict the convergence of the collimated beam in the interferometer. This is because convergent rays are modulated at different frequencies as the path difference is varied. Such an aperture is called a Jacquinot stop. For a given resolution and wavelength this circular aperture allows more light through than a slit, resulting in a higher signal-to-noise ratio. The wavelength accuracy or Connes's advantage (named after Janine Connes).
The Edman degradation is an alternative method for peptide sequencing that cleaves amino acid residues from the N-terminus of a peptide. In 1950 Edman designed a reaction with phenylthiocyanate (the idea for which was borrowed from a 1927 study by Bergmann, Kann and Miekeley ) to give phenylthiocarbamyl peptides followed by hydrolysis under relatively mild conditions to cleave N-terminal amino acid as phenylthiohydantoin. Phenylthiohydantoin is stable enough to undergo various sequencing procedures such as those which involve chromatography and mass spectrometry. This was an improvement on an earlier method proposed by Abderhalden and Brockmann in 1930 that demonstrated N-terminal amino acid conversion to a hydantoin under stronger hydrolytic conditions, where some cleavage of the residual peptide proved problematic. The primary advantage the Edman degradation has over the Bergmann degradation is the ease with which the residual peptide can re-enter the process due to retention of its structure throughout sequential cleaving. Repetition of the Bergmann degradation is presumably not as straightforward, as the remaining peptide is in amide form.
TBR1 was identified in 1995 by the Nina Ireland Laboratory of Developmental Neurobiology Center at the University of California, San Francisco. The gene, initially named TES-56, was found to be largely expressed in the telencephalic vesicles of the developing forebrain of mice. The protein product of TES-56 was discovered to be homologous to the Brachyury protein, a T-box transcription factor, which plays a role in establishing symmetry during embryonic development. Thus, due to its relation to T-box genes (such as Tbx-1, Tbx-2, Tbx-3), TES-56 was renamed TBR1. The human TBR1 gene is located on the q arm of the positive strand of chromosome 2. It is 8,954 base pairs in length. TBR1 is one of the three genes that make up the TBR1 subfamily of T-box genes. The two other genes that form the TBR1 subfamily are EOMES (also known as TBR2) and TBX21 (also known as T-BET). TBR1 is also known as T-box Brain Protein, T-Brain 1, and TES-56. The encoded protein consists of 682 amino acid residues and has a predicted molecular weight of 74,053 Da. It is composed of 6 exons.
According to news reports, the execution of Ronald Bert Smith in the state of Alabama on 8 December 2016 allegedly went awry due to the fact he displayed movement soon after midazolam was injected, although prison staff confirmed twice that he was still unconscious before injecting the two fatal drugs. This controversy again stirred concern among the public regarding the effectiveness of the drug in question. In October 2016, the state of Ohio announced that it would resume executions in January 2017, using a formulation of midazolam, vecuronium bromide, and potassium chloride, but this was blocked by a federal judge. On 26 July 2017, Ronald Phillips was executed with a three-drug cocktail including midazolam after the Supreme Court refused to grant a stay. Prior to this, the last execution in Ohio had been that of Dennis McGuire. Murderer Gary Otte's lawyers unsuccessfully challenged his Ohio execution, arguing that midazolam might not protect him from serious pain when the other drugs are administered. He was pronounced dead without incident in about 14 minutes on 13 September 2017. In April 2017, the state of Arkansas carried out a double-execution, of Jack Harold Jones, 52, and Marcel Williams, 46. Arkansas attempted to execute eight people before its supply of midazolam expired on 30 April 2017. Two of them were granted a stay of execution, and another, Ledell Lee, 51, was executed on 20 April 2017. In October 2021, the state of Oklahoma executed inmate John Marion Grant, 60, using midazolam as part of its three-drug cocktail hours after the U.S.
Sources: en.wikipedia.org
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.
No. The two peptides share part of a name but differ in length, sequence, and net charge. Literature searches that treat them as one compound return misleading results.
Solid-phase peptide synthesis is the usual route, and recombinant expression has also been described. Both approaches produce material matching the natural sequence.
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.