This is a working overview of Thymalfasin, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-01-05. Anything still debated is marked as such rather than presented as settled.
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.
The peptide was identified during work in the 1970s on thymosin fraction 5, a partially purified extract of calf thymus. Investigators separated that mixture and characterized individual components, one of which they named thymosin alpha-1. The same compound later received the international nonproprietary name thymalfasin. Commercial material is produced by solid-phase peptide synthesis rather than by extraction, so synthetic and natural forms share an identical sequence. Naming conventions vary across the literature, and readers should distinguish the alpha-1 peptide from other thymosins that have unrelated sequences and functions.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography, which separates the peptide from closely related impurities and from truncated or oxidized variants. Mass spectrometry supplies the molecular mass and confirms the expected sequence length, while amino acid analysis can be used to check composition. Because the molecule has no chromophore beyond the peptide backbone, ultraviolet detection is typically performed at a low wavelength, where baseline interference from solvents and buffers is a practical concern. Water content and counter-ion content are often reported alongside purity.
Practical handling focuses on limiting adsorption and contamination. The peptide dissolves readily in water, and dilute solutions tend to adhere to plastic and glass surfaces, so an inert carrier protein or a defined buffer can reduce losses in laboratory work. Workers also record the counter-ion form, since an acetate or trifluoroacetate salt changes the mass balance of the weighed powder. Documentation of lot number, purity value, and storage history supports reproducibility when results from different laboratories are compared.
| 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 |
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.
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 testing for thymosin alpha 1 relies mainly on reversed-phase high-performance liquid chromatography and mass spectrometry. Chromatography separates the parent peptide from truncated or modified variants, while mass spectrometry confirms the expected molecular mass. Amino acid analysis and peptide mapping provide additional sequence confirmation. Counterion content, water content, and residual solvents are measured separately as part of specification testing. No single method captures every attribute, so laboratories combine several techniques.
The peptide lacks cysteine, methionine, and tryptophan, so disulfide scrambling and sulfur oxidation are not major degradation routes. Instead, aspartate residues can undergo isomerization or cyclization to succinimide intermediates, generating isoaspartate variants. Hydrolysis of peptide bonds also occurs slowly in solution. These changes may reduce biological activity even when the main peak remains detectable. Stability studies therefore track both potency and the appearance of related substances.
=== First representation === A copper vaporizer block is electrically heated with two 100 watt cartridge heaters and a stainless steel capillary allow introduction of sample and consequent partial vaporization. The capillary and the vaporizer block are soldered together to ensure stable thermal contact. The resultant supersonic jet then passes through the ion source for introduction into the quadrupole mass spectrometer.
=== Activation === PAR1 is activated when the terminal 41 amino acids of its N-terminus are cleaved by thrombin, a serine protease. Thrombin recognizes PAR1 by a Lysine-Aspartate-Proline-Arginine-Serine sequence at the N-terminal, where it cuts the peptide bond between Arginine-41 and Serine-42. The affinity of thrombin to this specific cleavage site in PAR1 is further aided by secondary interactions between thrombin's exosite and an acidic region of amino acid residues located C-terminal to Ser-42. This proteolytic cleavage is irreversible and the loose peptide, often referred to as parstatin, is then released outside of the cell. The newly revealed N-terminus acts as a tethered ligand that binds to a binding region between extracellular loops 3 and 4 of PAR1, therefore activating the protein. The binding instigates conformational changes in the protein that ultimately allow for the binding of G-proteins to sites on the intracellular region of PAR1.
Next come the 4p orbitals, completing the row, which are filled progressively by gallium ([Ar] 3d10 4s2 4p1) through krypton ([Ar] 3d10 4s2 4p6), in a manner analogous to the previous p-block elements. From gallium onwards, the 3d orbitals form part of the electronic core, and no longer participate in chemistry. The s- and p-block elements, which fill their outer shells, are called main-group elements; the d-block elements (coloured blue below), which fill an inner shell, are called transition elements (or transition metals, since they are all metals). The next 18 elements fill the 5s orbitals (rubidium and strontium), then 4d (yttrium through cadmium, again with a few anomalies along the way), and then 5p (indium through xenon). Again, from indium onward the 4d orbitals are in the core. Hence the fifth row has the same structure as the fourth.
== Preparations == The Gemini 4 spacecraft completed major manufacturing activity, module tests, and equipment installation at McDonnell at the end of January 1965. The spacecraft was mated to the Titan II launch vehicle at Cape Canaveral Launch Complex 19 on April 23, 1965. Final system tests were performed over several additional weeks. NASA leadership approved the Gemini 4 EVA plan on May 25, 1965; the public was informed on the same day
Sources: en.wikipedia.org
=== Adults === The World Health Organization recommends a minimal acceptable intake of approximately 1.3 mg/day. These values are considered to be adequate and safe for most of the general population. In North America, the U.S. Institute of Medicine (IOM) set the Recommended Dietary Allowance (RDA) for copper for healthy adult men and women at 0.9 mg/day. As for safety, the IOM also sets Tolerable upper intake levels (ULs) for vitamins and minerals when evidence is sufficient. In the case of copper, the UL is set at 10 mg/day. The European Food Safety Authority reviewed the same safety question and set its UL at 5 mg/day.
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Follicle-stimulating hormone (FSH) is a gonadotropin, a glycoprotein polypeptide hormone. FSH is synthesized and secreted by the gonadotropic cells of the anterior pituitary gland and regulates the development, growth, pubertal maturation, and reproductive processes of the body. FSH and luteinizing hormone (LH) work together in the reproductive system.
== Developments == A water-soluble prodrug, fospropofol, has been developed and tested with positive results. Fospropofol is rapidly broken down by the enzyme alkaline phosphatase to form propofol. Marketed as Lusedra, this formulation may not produce the pain at the injection site that often occurs with the conventional form of the drug. The U.S. Food and Drug Administration (FDA) approved the product in 2008. By incorporation of an azobenzene unit, a photoswitchable version of propofol (AP2) was developed in 2012 that allows for optical control of GABAA receptors with light. In 2013, a propofol binding site on mammalian GABAA receptors has been identified by photolabeling using a diazirine derivative. Additionally, it was shown that the hyaluronan polymer present in the synovia can be protected from free-radical depolymerization by propofol. Ciprofol is another derivative of propofol that is 4–6 times more potent than propofol. As of 2022 it is undergoing Phase III trials. Ciprofol appears to have a lower incidence of injection site pain and respiratory depression than propofol. Propofol has also been studied for treatment resistant depression.
To treat complications, medications can be prescribed including midodrine for autonomic neuropathy, amiodarone for patients with atrial fibrillation to prevent arrhythmias, and warfarin used after a cardioembolic episode. Familial (ATTRm-CM) Treatment: In recent years there have been developments in the treatment of Familial/Transthyretin cardiac amyloidosis including methods to suppress transthyretin production, stabilize amyloid fibrils, and medications that can destroy already existing fibrils. For familial amyloidosis, ACE-inhibitors and beta-blockers can be prescribed if there is no autonomic neuropathy.
Sources: en.wikipedia.org
=== Monitor shipments === Temperature sensitive products such as foods, pharmaceuticals, and some chemicals are often monitored during shipment and logistics operations. Exposure to temperatures outside of an acceptable range, for a critical time period, can degrade the product or shorten shelf life. Regulations and contracts make temperature monitoring mandatory for some products. Battery-powered, formerly mechanical, the data logger is today an electronic device that can be programmed to record individual values over periods of a few hours to several months. Most are used to monitor temperature conditions, and some versions can also measure the relative humidity. Data loggers are often small enough to be placed inside an insulated shipping container or directly attached to a product inside a refrigerator truck or a refrigerated container. These monitor the temperature of the product being shipped. Some data loggers are placed on the outside of the package or in the truck or intermodal container to monitor the air temperature. Placement of data loggers and sensors is critical: Studies have shown that temperatures inside a truck or intermodal container are strongly affected by proximity to exterior walls and roof and to locations on the lading. Modern digital data loggers are very portable and record the actual times and temperatures. This information can be used to model product degradation and to pinpoint the location and cause of excessive exposure.
=== July === July 27, 2011: United Kingdom After figures showed that the 0.5% contraction in Q4 2010 was cancelled out by a 0.5% rise in Q1 2011, growth estimates from the ONS suggest that the growth in the UK is slowing down, after figures of 0.2% GDP increase was posted. Sovereign debt in the Eurozone and EU cause the stock market to crash from a FTSE-100 high of 6100 points to just above 5000.
== RM-ODP and UML == Currently there is growing interest in the use of UML for system modelling. However, there is no widely agreed approach to the structuring of such specifications. This adds to the cost of adopting the use of UML for system specification, hampers communication between system developers and makes it difficult to relate or merge system specifications where there is a need to integrate IT systems. Although the ODP reference model provides abstract languages for the relevant concepts, it does not prescribe particular notations to be used in the individual viewpoints. The viewpoint languages defined in the reference model are abstract languages in the sense that they define what concepts should be used, not how they should be represented. This lack of precise notations for expressing the different models involved in a multi-viewpoint specification of a system is a common feature for most enterprise architectural approaches, including the Zachman Framework, the "4+1" model, or the RM-ODP. These approaches were consciously defined in a notation- and representation-neutral manner to increase their use and flexibility. However, this makes more difficult, among other things, the development of industrial tools for modeling the viewpoint specifications, the formal analysis of the specifications produced, and the possible derivation of implementations from the system specifications. In order to address these issues, ISO/IEC and the ITU-T started a joint project in 2004: "ITU-T Rec.
In APCI the ionization occurs at atmospheric pressure with ions produced by corona discharges on a solvent spray, and it is often coupled with high-performance liquid chromatography (HPLC) which provides quality determination of polar and ionic compounds in the collected atmospheric aerosols. The use of APCI allows for the sampling of the filters without the need of solvents for the extraction. The APCI is typically connected to a quadruple mass spectrometer. Other ionization methods are often used for off-line mass spectrometer inductively coupled plasma (ICP). ICP is commonly used in the elemental analysis of trace metals, and can be used to determine the source of the particles and their health effects. There are also a range of soft ionisation techniques available for assessing the molecular composition of aerosol particles in greater detail, such as electrospray ionization, which result in less fragmentation of compounds within the aerosol. These techniques are only beneficial when coupled with a high or ultra-high resolution mass spectrometer, such as an FTICR-MS or an Orbitrap, as very high resolution is needed to differentiate between the high number of compounds present.
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.
Cool storage below freezing is usual for long-term retention, with a desiccant and protection from light. Portions are often split before first use to avoid repeated handling.