The short version of thymalfasin fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-08-20. Anything still debated is marked as such rather than presented as settled.
Thymosin beta-4 is a separate 43-residue peptide that binds actin and participates in cell migration; it shares no sequence similarity with thymosin alpha-1 despite the common family name. Other preparative materials, such as thymosin fraction 5 and thymopoietin, contain distinct mixtures or peptides. The shared thymosin label reflects the tissue of origin used in early purification, not a common structural core. Treating these molecules as interchangeable is a frequent source of confusion in laboratory reports and in popular summaries alike.
Thymosin alpha-1 is a synthetic peptide of 28 amino acid residues that corresponds to a naturally occurring fragment first isolated from thymus tissue. Its chain is acetylated at the amino terminus, a modification that shields the peptide from rapid cleavage by aminopeptidases. The molecule carries a net negative charge at physiological pH and dissolves freely in water. Researchers classify it as an immune-modulating agent rather than a classical hormone, because it acts on several cell types of both the innate and the adaptive immune system.
Biologically, the peptide is studied mainly in the context of immune cell development and regulation. It is produced in the thymus and in several other tissues, and it appears to influence the maturation and activity of T cells and other immune populations. Laboratory work describes effects on cytokine production, on the balance between T cell subsets, and on the function of dendritic cells. Much of this evidence comes from cell culture and animal models, so the extent to which the same pathways operate in humans remains an open question.
Clinical interest has centered on chronic viral hepatitis, on immune restoration in various conditions, and on use as an adjuvant intended to improve responses to vaccines. Trials have reported mixed results, and regulatory status differs sharply between countries; in some places it is a prescription product, while elsewhere it is sold without an approved therapeutic indication. Because published studies vary widely in design, population, and endpoints, comparisons across them are difficult and no single conclusion covers the whole literature.
| Property | Value | Notes |
|---|---|---|
| Molecular mass | About 3.1 kDa | 28 residues, N-terminally acetylated |
| Appearance | White to off-white powder | Lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in aqueous buffers |
| Storage temperature | 2 to 8 °C | Protect from light and moisture |
| Common synonyms | Thymalfasin; Tα1 | Same peptide sequence |
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 a short peptide first isolated from bovine thymus tissue in the early 1970s during fractionation work aimed at identifying factors that influence T cell development. It belongs to a family of acidic thymic peptides, and the original preparations contained several components that were later separated by chromatography. The compound is now produced synthetically rather than extracted from tissue, which removes batch variability tied to animal sourcing. Researchers describe it as an immunomodulatory peptide because laboratory studies show effects on several cell types of the innate and adaptive immune systems.
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.
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 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.
Taylor (2015) reported that the perceived self-efficacy and perceived helplessness subscales tended to estimate scores reliably across levels of the latent variables except among respondents with exceptionally low levels of perceived helplessness and exceptionally high levels of perceived self-efficacy. Finally, much less is known about the reliability of scores from the 4-item form.
=== Magic numbers === As early as 1914, the possible existence of superheavy elements with atomic numbers well beyond that of uranium—then the heaviest known element—was suggested, when German physicist Richard Swinne proposed that superheavy elements around Z = 108 were a source of radiation in cosmic rays. Although he did not make any definitive observations, he hypothesized in 1931 that transuranium elements around Z = 100 or Z = 108 may be relatively long-lived and possibly exist in nature. In 1955, American physicist John Archibald Wheeler also proposed the existence of these elements; he is credited with the first usage of the term "superheavy element" in a 1958 paper published with Frederick Werner. This idea did not attract wide interest until a decade later, after improvements in the nuclear shell model. In this model, the atomic nucleus is built up in "shells", analogous to electron shells in atoms. Independently of each other, neutrons and protons have energy levels that are normally close together, but after a given shell is filled, it takes substantially more energy to start filling the next. Thus, the binding energy per nucleon reaches a local maximum and nuclei with filled shells are more stable than those without. This theory of a nuclear shell model originates in the 1930s, but it was not until 1949 that German physicists Maria Goeppert Mayer and Johannes Hans Daniel Jensen et al. independently devised the correct formulation. The numbers of nucleons for which shells are filled are called magic numbers.
By targeting the biological processes responsible for aging, researchers seek to develop interventions capable of delaying or preventing multiple age-related diseases simultaneously while extending healthspan and maintaining independence. Particular emphasis is placed on addressing health disparities and improving outcomes among the diverse and medically underserved populations of South Texas, who experience an earlier onset of chronic disease and functional decline than many other U.S. populations. The Pepper Center provides a comprehensive translational research infrastructure that supports investigators from laboratory discovery through clinical implementation. Its integrated research cores offer expertise in clinical investigation, geriatric phenotyping, biostatistics, epidemiology, population science, biomarker development, physiology, metabolism, and implementation science. These shared resources enable investigators to design and conduct highly sophisticated clinical and translational studies focused on preserving muscle function, mobility, cognition, metabolic health, and resilience in aging adults. The Center also serves as a hub for multidisciplinary collaborations that bridge preclinical discoveries with human clinical trials, accelerating the translation of promising interventions into evidence-based strategies that can be implemented in clinical practice. A defining feature of the San Antonio Pepper Center is its commitment to developing the next generation of clinician-scientists and translational investigators in aging research.
== Effects of Algicidal Bacteria on Algae == Algicidal bacteria can cause harm to algae in multiple different ways. Depending on the type of algae and type of bacteria, the mechanisms and resulting effects can vary.
Sources: en.wikipedia.org
== History == Kwashiorkor was present in the world long before 1933 when Cicely Williams published research that took the Ga name for the disease. There were already many names for the illness which referenced the cessation of breastfeeding, or the consumption of monotonous diets high in starch. However, Williams was the first to suggest that this might be a deficiency of protein or an amino acid. Despite publishing in 1933, it was only in 1949 that the World Health Organization officially recognized kwashiorkor as a public health concern. This period also correlated with the promotion of infant formula, often by European colonial powers. The substitution of formula for breastmilk contributed significantly to the increasing visibility of kwashiorkor throughout the twentieth century. Cicely Williams later described the promotion of formula as "the most criminal form of sedition, and that those deaths should be regarded as murder." These arguments underpinned the 1970s Nestlé boycott.
Liberation – When the active pharmaceutical ingredient is released from its pharmaceutical formulation and becomes available for absorption. Absorption – How the drug enters the bloodstream. Distribution – How the drug spreads throughout the body's tissue and fluids. Metabolism – How the drug is chemically altered, primarily in the liver. Excretion – How the drug and its metabolites are eliminated, mainly through the kidneys.
=== Gene cluster === The study of the genetic cluster encoding the biosynthesis of teicoplanin identified 49 putative open reading frames (ORFs) involved in the compound's biosynthesis, export, resistance, and regulation. Thirty-five of these ORFs are similar to those found in other glycopeptide gene clusters. The function of each of these genes is described by Li and co-workers. A summary of the gene layout and purpose is shown below. Gene layout. The genes are numbered. The letters L and R designate transcriptional direction. The presence of the * symbol means a gene is found after NRPs, which are represented by A, B, C, and D. Based on the figure from: Li, T-L.; Huang, F.; Haydock, S. F.; Mironenko, T.; Leadlay, P. F.; Spencer, J. B. Chemistry & Biology. 2004, 11, p. 109. [11-L] [10-L] [9-R] [8-R] [7-R] [6-R] [5-R] [4-L][3-L] [2-L] [1-R] [A-R] [B-R] [C-R] [D-R] [1*-R] [2*-R] [3*-R] [4*-R] [5*-R] [6*-R] [7*-R] [8*-R] [9*-R] [10*-R] [11*-R] [12*-R] [13*-R] [14*-R] [15*-R] [16*-R] [17*-R] [18*-R] [19*-R] [20*-R] [21*-R] [22*-R] [23*-R] [24*-R] [25*-L] [26*-L] [27*-R] [28*-R] [29*-R] [30*-R][31*-R] [32*-L] [33*-L] [34*-R]
== Adverse effects == Side effects are similar to those of buprenorphine and other opioids. In addition, naloxone can induce withdrawal symptoms in people who are chemically dependent on opioids. The most common side effects (in order of most to least common) of sublingual tablets include headaches, opioid withdrawal syndrome, pain, nausea, increased sweating, and difficulty sleeping. The most common side effects seen in film formulations are tongue pain, decreased sensation and redness in the mouth, headache, nausea, vomiting, excessive sweating, constipation, signs and symptoms of opioid withdrawal, sleeping difficulties, pain, and swelling of the extremities. Post-approval, the most frequently reported side effects of buprenorphine/naloxone in sublingual strip form (i.e. Suboxone strips) are peripheral edema, stomatitis, glossitis, blistering of the mouth, and mouth ulcers (mouth sores). Use of buprenorphine/naloxone may also increase the risk of developing certain dental problems (including tooth decay and tooth loss). Buprenorphine/naloxone has a milder side effect profile than methadone and limited respiratory effects, due to both agonist/antagonist effects. But buprenorphine/naloxone may be less safe than methadone in people with stable liver disease since it can elevate liver enzymes.
== Mechanism of action == Pembrolizumab is a therapeutic antibody that binds to and blocks PD-1 located on lymphocytes. This receptor is generally responsible for preventing the immune system from attacking the body's own tissues; it is a so-called immune checkpoint. Normally, the PD-1 receptor on activated T-cells binds to the PD-L1 or PD-L2 ligands present on normal cells in the body, deactivating any potential cell-mediated immune response against these cells. Many cancers make proteins such as PD-L1 that also bind to the PD-1 receptor, thus shutting down the ability of the body to kill the cancer. Pembrolizumab works by inhibiting lymphocytes' PD-1 receptors, blocking the ligands that would deactivate it and prevent an immune response. This allows the immune system to target and destroy cancer cells, but also blocks a key mechanism preventing the immune system from attacking the body itself. This checkpoint inhibitor function of pembrolizumab thus has immune-dysfunction side effects as a result. Tumors often have mutations that cause impaired DNA mismatch repair. This in turn often results in microsatellite instability allowing the tumor to generate numerous mutant proteins that could serve as tumor antigens, triggering an immune response against the tumor. By preventing the self-checkpoint system from blocking the T-cells, pembrolizumab appears to facilitate clearance of any such tumor by the immune system.
Sources: en.wikipedia.org
Estrogen sulfates like estradiol sulfate or estrone sulfate are about twice as potent as the corresponding free estrogens in terms of estrogenic effect when given orally to rodents. This in part led to the introduction of conjugated estrogens (Premarin), which are primarily estrone sulfate, in 1941. Although inactive at steroid hormone receptors, E2S has been found to act as a potent inhibitor of glutathione S-transferase, an enzyme that contributes to the inactivation of estradiol via conversion of it into an estradiol-glutathione conjugate. As such, E2S can indirectly serve as a positive effector of estrogen signaling. Estradiol levels are about 1.5- to 4-fold higher than E2S levels in women. This is in contrast to E1S, the levels of which are about 10 to 15 times higher than those of estrone. E2S at an oral dosage of 5 mg/day in women resulted in inhibition of ovulation in 89% of cycles (47 of 53).
A considerable amount of new knowledge about plant function comes from studies of the molecular genetics of model plants such as the Thale cress, Arabidopsis thaliana, a weedy species in the mustard family (Brassicaceae). The genome or hereditary information contained in the genes of this species is encoded by about 135 million base pairs of DNA, forming one of the smallest genomes among flowering plants. Arabidopsis was the first plant to have its genome sequenced, in 2000. The sequencing of some other relatively small genomes, of rice (Oryza sativa) and Brachypodium distachyon, has made them important model species for understanding the genetics, cellular and molecular biology of cereals, grasses and monocots generally. Model plants such as Arabidopsis thaliana are used for studying the molecular biology of plant cells and the chloroplast. Ideally, these organisms have small genomes that are well known or completely sequenced, small stature and short generation times. Corn has been used to study mechanisms of photosynthesis and phloem loading of sugar in C4 plants. The single-celled green alga Chlamydomonas reinhardtii, while not an embryophyte itself, contains a green-pigmented chloroplast related to that of land plants, making it useful for study. A red alga, Cyanidioschyzon merolae, has also been used to study some basic chloroplast functions. Spinach, peas, soybeans and a moss Physcomitrella patens are commonly used to study plant cell biology.
Anatomically embalmed cadavers have a typically uniform grey colouration, due both to the high formaldehyde concentration mixed with the blood and the lack of red colouration agents commonly added to standard, nonmedical, embalming fluids. Formaldehyde mixed with blood causes the grey discoloration also known as "formaldehyde grey" or "embalmer's grey". A new embalming technique developed gradually since the 1960s by anatomist Walter Thiel at the Graz Anatomy Institute in Austria has been the subject of various academic papers, as the cadaver retains the body's natural color, texture and plasticity after the process. The method uses 4-chloro-3-methylphenol and various salts for fixation, boric acid for disinfection, and ethylene glycol for the preservation of tissue plasticity. The embalmed cadavers are used in anatomical research, surgical and anaesthesia training, preoperative test procedures, CT image quality studies.
== Signs and symptoms == Selenium deficiency in combination with Coxsackievirus infection can lead to Keshan disease, which is potentially fatal. Selenium deficiency also contributes (along with iodine deficiency) to Kashin-Beck disease. The primary symptom of Keshan disease is myocardial necrosis, leading to the weakening of the heart. Kashin-Beck disease results in atrophy, degeneration, and necrosis of cartilage tissue. Keshan disease also makes the body more susceptible to illness caused by other nutritional, biochemical, or infectious diseases. Selenium is also necessary for the conversion of the thyroid hormone thyroxine (T4) into its more active counterpart triiodothyronine (T3), and as such a deficiency can cause symptoms of hypothyroidism, including extreme fatigue, mental slowing, goiter, cretinism, and recurrent miscarriage.
In the case of crystallins, the genes must maintain sequences for catalytic function and transparency maintenance function. The abundant lens crystallins have been generally viewed as static proteins serving a strictly structural role in transparency and cataract. However, recent studies have shown that the lens crystallins are much more diverse than previously recognized and that many are related or identical to metabolic enzymes and stress proteins found in numerous tissues. Unlike other proteins performing highly specialized tasks, such as globin or rhodopsin, the crystallins are very diverse and show numerous species differences. Essentially all vertebrate lenses contain representatives of the α and β/γ crystallins, the "ubiquitous crystallins", which are themselves heterogeneous, and only few species or selected taxonomic groups use entirely different proteins as lens crystallins. This paradox of crystallins being highly conserved in sequence while extremely diverse in number and distribution shows that many crystallins have vital functions outside the lens and cornea, and this multi-functionality of the crystallins is achieved by moonlighting.
Sources: en.wikipedia.org
It is a 28-residue synthetic peptide studied as an immune-modulating agent and approved as a drug in some countries. The sequence matches a naturally occurring fragment isolated from thymus tissue. It is not a hormone in the endocrine sense.
The name traces back to thymosin fraction 5, a crude thymus extract examined in the 1970s. Individual peptides in that mixture were labeled with Greek letters, and alpha-1 was one of them. The international nonproprietary name thymalfasin was assigned later.
No. Thymosin beta-4 contains 43 residues and binds actin, while thymosin alpha-1 contains 28 residues and acts on immune cells. The two sit in a historical naming group but share no sequence similarity, and they are not substitutes for one another.
The name reflects an early convention for naming thymus-derived fractions. The peptide is characterized and measured as a defined molecule, and it does not operate through a single classical endocrine axis.