This is a working overview of PTMA gene, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-04-02 and is reviewed periodically as new material appears.
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.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, which separates the target peptide from truncated or chemically modified byproducts. Mass spectrometry confirms the expected molecular mass and can indicate acetylation state or sequence errors. Amino acid analysis and peptide mapping supply complementary sequence-level information, while endotoxin testing is relevant for preparations intended for cell or animal work. Purity figures reported by suppliers refer to the method used and are not directly comparable across laboratories unless conditions are stated.
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.
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.
The peptide was described in the 1970s as a component of thymic extracts, and early research focused on restoring immune function in immunodeficiency states. A synthetic version entered clinical development in the 1980s and is approved as a drug in several countries for conditions such as chronic hepatitis B and certain immunodeficiencies. Approval status varies widely by jurisdiction, and in the United States it is not an approved therapeutic. Regulatory and clinical positions differ, so statements about efficacy should be tied to specific indications and studies.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white lyophilized powder | Visual description varies by batch |
| Solubility | Freely soluble in water | Aqueous buffers are commonly used |
| Typical storage temperature | -20 °C or below for powder | Reconstituted liquid kept at 2-8 °C short term |
| Purity method | Reversed-phase HPLC | Value derived from peak area integration |
| Identity method | Mass spectrometry | Confirms mass and sequence integrity |
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。
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。
The molecule consists of 28 amino acid residues with an acetyl group attached to the N-terminal serine. Its sequence is acidic overall, with several glutamic and aspartic acid residues distributed along the chain and no cysteine, so disulfide bridges do not form. The peptide carries a net negative charge at physiological pH. Because the N-terminus is blocked, the intact molecule resists degradation by many aminopeptidases, which contributes to its stability in biological fluids.
The peptide is generated in cells by cleavage of prothymosin alpha, a larger acidic protein encoded by the PTMA gene. Prothymosin alpha is expressed in many tissues, not only in the thymus, and its functions include nuclear roles in chromatin-related processes. The 28-residue fragment corresponds to the N-terminal portion of that precursor. How the cleavage occurs and how the fragment's concentration is regulated remain open questions; circulating amounts are small and difficult to measure reliably with routine assays.
Thymosin alpha 1 is approved as a medicine in several countries, including Italy and China, for indications such as chronic hepatitis B and as an immune adjuvant. It is not approved by the United States Food and Drug Administration as a therapeutic product. In research settings the peptide appears in studies of sepsis, vaccine response, and oncology support, often with mixed or inconclusive results. The evidence base is uneven, and reviews note that many trials were small. Regulatory status therefore differs widely between jurisdictions.
Thymosin alpha 1 is a synthetic 28-amino-acid peptide first isolated in 1966 from thymosin fraction 5, a bovine thymus extract. Its chain begins with an acetylated serine residue and ends with asparagine. The native peptide carries a molecular mass near 3,108 daltons. Researchers classify it as an immunomodulatory agent rather than a hormone with a single endocrine target. Early work framed it as a thymus-derived factor that supports T-cell maturation. The synthetic form used in research and clinical products matches the natural sequence.
Immune signaling studies link thymosin alpha 1 to Toll-like receptor pathways, particularly TLR2 and TLR9, on dendritic cells and other antigen-presenting cells. Activation of these receptors promotes maturation of T cells and increases natural killer cell activity. The peptide shifts cytokine output toward a T helper 1 profile, raising interferon gamma and interleukin 2 while modulating interleukin 10. Whether these effects translate into clinical benefit for any specific disease remains a subject of debate. Reported outcomes vary across trials and populations.
=== Cholesterol clearance === Synthetic platelets are being explored for their potential in cholesterol clearance by facilitating the targeted removal of cholesterol from the bloodstream, offering a novel approach to treating hypercholesterolemia and preventing cardiovascular diseases. Elevated low-density lipoprotein cholesterol (LDL-C) is a key contributor to coronary heart disease, largely regulated by the interaction between LDL receptors (LDLR) and Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9). Since PCSK9 reduces LDLR availability, inhibiting it can enhance LDL-C clearance. To explore this, researchers designed platelet-mimicking nanoparticles to deliver siRNA targeting Pcsk9. These nanoparticles effectively lowered Pcsk9 mRNA levels by 66% in cell studies and reduced plasma LDL-C by 28% in animal models, without significantly altering high-density lipoprotein cholesterol (HDL-C) or triglycerides (TGs). This strategy demonstrates the potential of biomimetic nanoparticles for RNA-based therapies aimed at treating high cholesterol.
== External links == The Regimental Association of the British South Africa Police Blue & Old Gold – The History of the British South Africa Police 1889–1890 Leopard – Land Mine Resisting Vehicle (Used by the BSAP) Rhodesia Patrol (1953 documentary film made by the BSAP)
Later she drew a distinction between their methods, arguing that Quimby's involved one mind healing another, while hers depended on a connection with Divine Mind. In February 1883, Julius Dresser, a former patient of Quimby's, accused Eddy in letters to The Boston Post of teaching Quimby's work as her own. In response Eddy disparaged Quimby as a mesmerist and said she had experimented with mental healing in or around 1853, nine years before she met him. She wrote later: "We caught some of his thoughts, and he caught some of ours; and both of us were pleased to say this to each other." The issue went to court in September 1883, when Eddy complained that her student Edward Arens had copied parts of Science and Health in a pamphlet, and Arens counter-claimed that Eddy had copied it from Quimby in the first place. Quimby's son was so unwilling to produce his father's manuscripts that he sent them out of the country (perhaps fearing litigation with Eddy or that someone would tamper with them), and Eddy won the case. Things were stirred up further by Eddy's pamphlet Historical Sketch of Metaphysical Healing (1885), in which she again called Quimby a mesmerist, and by the publication of Julius Dresser's The True History of Mental Healing (1887). The charge that Christian Science came from Quimby, not divine revelation, stemmed in part from Eddy's use of Quimby's manuscript (right) when teaching Sally Wentworth and others in 1868–1870. Eddy said she had helped to fix Quimby's unpublished work, and now stood accused of having copied her own corrections. Against this, Lyman P.
Sources: en.wikipedia.org
The expansion of Toronto in the east, in the 19th century, led to the development of housing stock along the Kingston Road and Danforth Road corridors in Scarborough. This led to the creation of a transit line. In 1893, the Toronto and Scarboro' Electric Railway, Light and Power Company built a single-track radial line along Kingston Road to Blantyre. Over the next 13 years this was extended to West Hill. In 1904, the line became the Scarboro Division of the Toronto and York Radial Railway. Service continued along this line until 1936 when it was replaced by bus service.
== History == The PUN was founded in 1957 as a political platform to support the presidential candidacy of "Papa Doc" Duvalier in the 1957 general election. In the aftermath of the July 1958 coup attempt, the Tonton Macoute — officially named Volunteers of the National Security (French: Volontaires de la Sécurité Nationale, VSN) — was formed as the paramilitary wing of the PUN. In 1963, other political parties in Haiti were outlawed, making the PUN the single political party of the nation. When "Papa Doc" Duvalier died in 1971, his son "Baby Doc" Duvalier succeeded him as the President of the country and the leader of the party. The party would remain in power until the fall and exile of "Baby Doc" Duvalier in 1986, at the height of the Anti-Duvalier protest movement, after which the party would enter a low profile stage, including the change of its name to National Progressive Party (French: Parti progressiste national, PPN). After the return of "Baby Doc" Duvalier from exile in 2011, the party began a process of reconstitution under its original name from 2014, and started opening departmental offices. Suffering a setback with the death of "Baby Doc" Duvalier in 2014, the party nominated Marc-Arthur Drouillard as its candidate in the 2015 presidential election. Towards that time, the legal representative of the party was Philomène Exe.
== Prevention == Researchers found environmental reservoirs of CRE bacteria in ICU sinks and drains. Despite multiple attempts to sterilize these sinks and drains, using detergents and steam, the hospital staff was unsuccessful in getting rid of the CRE. Due to the bacterial resistance to cleaning measures, staff should take extreme precaution in maintaining sterile environments in hospitals not yet infected with the CRE-resistant bacteria. A major means of transmission is through sinks, so staff should take extra precaution in maintaining sterile conditions. Hospitals could reduce transmission by creating sinks with designs that could reduce backsplash. Another method to reduce transmission from sink to sink is to have sink brushes in each room that would be for cleaning that individual sink alone. Hospital staff should be trained to never dispose of clinical waste down the sinks in patient rooms. A hospital in Melbourne, Australia, implemented similar strategies as these to reduce transmission and prevent further infection of more ICU patients. Armed with the knowledge of their status as CRE transmission sites, hospitals must take special care to monitor CRE outbreaks within their wards. Efficient and accurate detection of CRE is the first step. Enterobacteriaceae are most commonly found in the intestinal flora. Using stool and rectal swabs are, thus, the most reliable methods for testing resistance. No billing code exists for CRE under Medicare or Medicaid, making it difficult to track on a national level in the U.S.
Sources: en.wikipedia.org
== Post-World-War-II life and work == In 1947, aged 31, Crick began studying biology and became part of an important migration of physical scientists into biological research. This migration was made possible by the newly won influence of physicists such as Sir John Randall, who had helped win the war with inventions such as radar. Crick had to adjust from the "elegance and deep simplicity" of physics to the "elaborate chemical mechanisms that natural selection had evolved over billions of years." He described this transition as, "almost as if one had to be born again". According to Crick, the experience of learning physics had taught him something important—hubris—and the conviction that since physics was already a success, great advances should also be possible in other sciences such as biology. Crick felt that this attitude encouraged him to be more daring than typical biologists who tended to concern themselves with the daunting problems of biology and not the past successes of physics. For the better part of two years, Crick worked on the physical properties of cytoplasm at Cambridge's Strangeways Research Laboratory, headed by Honor Bridget Fell, with a Medical Research Council studentship, until he joined Max Perutz and John Kendrew at the Cavendish Laboratory. The Cavendish Laboratory at Cambridge was under the general direction of Sir Lawrence Bragg, who had won the Nobel Prize in 1915 at the age of 25.
== Connective tissue-activating peptide III == Connective tissue-activating peptide III (CTAP-III), also called Low-affinity platelet factor IV (LA-PF4), is a protein that corresponds to positions 44-128 of PPBP. This protein has mitogenic effects: stimulating DNA synthesis and mitosis. It also triggers prostaglandin E2 secretion and synthesis of hyaluronic acid and sulfated glycosaminoglycan.
Outbreaks of disease Food-born illness Bioterrorism Natural disasters APHL plays a critical role in crisis response to these public health emergencies through the Laboratory Response Network (LRN). The LRN was formed in 1999 in a cooperative effort between APHL, the CDC and FBI to rapidly detect, and respond to public health emergencies. The Department of Defense has joined in the effort to support biological response activities. In addition to their leadership during times of crisis, APHL has a strong focus on preparing public health laboratories on how to respond to emergencies when they happen through training and capacity-building, as well as creating model frameworks that labs around the country can use in order to have procedures in place to handle a crisis when it happens.
Chromatin remodelers in the INO80 subfamily are made of multiple subunit complexes with split ATPase domains. The INO80 subfamily's protein domains are an N-terminus, two RuvB-like proteins (Rvb1 and Rvb2), and a C-terminus. The ATPase domain of the N-terminus functions in the identification of DNA damage and aids in the stability of telomeres. A long insertion in the ATPase domain is what recruits the Rvb1 and Rvb2 helicases. These helicases contribute to genome maintenance and are unique to the INO80 subfamily of chromatin remodeling complexes. This subfamily also contains an Arp4-actin complex that aids in stability of genes. The Arp5 subunit is required for ATPase function, binding to the DNA, and relocation of nucleosomes.
Sources: en.wikipedia.org
Cold storage slows the chemical degradation reactions that occur in solution. Lyophilized powder is more stable than reconstituted liquid and tolerates longer storage periods. Repeated temperature cycling should still be avoided because it can drive aggregation and loss of material.
Mass spectrometry is the standard confirmation of molecular mass and acetylation state. Chromatography establishes purity but does not identify the molecule on its own. The two techniques are normally applied together during verification.
No, because the reported value reflects the detection method and wavelength used, which vary between laboratories. A number stated without method details cannot be compared directly with another supplier's figure. Requesting the chromatogram and the method conditions is a common way to interpret it.
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.