The short version of synthetic peptide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-02-25. 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.
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.
Long-term storage is generally at minus twenty degrees Celsius or colder, preferably desiccated and protected from light. Lyophilized material is more stable than reconstituted solution, which degrades faster at room temperature. Stability depends on pH, ionic strength, and the presence of oxidising agents. Published stability data for the peptide are limited, so storage claims in catalogues should be treated as general guidance rather than measured guarantees. Freeze-thaw cycles are kept to a minimum.
Identity and purity are normally confirmed by reversed-phase high-performance liquid chromatography and mass spectrometry. The expected mass for the acetylated 28-residue peptide is close to 3108 daltons, and a mass shift indicates a modification or truncation. Peptide mapping after enzymatic digestion can resolve sequence-level questions. Counter-ion content, water content, and residual solvents are separate quality attributes that a certificate of analysis may or may not report. Aggregation is monitored by size-exclusion chromatography when relevant.
Thymosin alpha-1 is supplied as a lyophilized powder in most research settings. The solid dissolves readily in water and in common aqueous buffers, and it is typically reconstituted shortly before use. Solutions are clear and colourless at ordinary working concentrations. Because the peptide is hygroscopic, weighing and reconstitution are usually performed with minimal exposure to ambient air. Aliquots are prepared to avoid repeated freeze-thaw cycles, and working solutions are kept cold.
| 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 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.
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.
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.
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=== Laboratory uses === In the laboratory, this compound is used in complexometric titrations. A variant of NTA is used for protein isolation and purification in the His-tag method. The modified NTA is used to immobilize nickel on a solid support. This allows purification of proteins containing a tag consisting of six histidine residues at either terminus. The His-tag binds the metal of metal chelator complexes. Previously, iminodiacetic acid was used for that purpose. Now, nitrilotriacetic acid is more commonly used. For laboratory uses, Ernst Hochuli et al. (1987) coupled the NTA ligand and nickel ions to agarose beads. This Ni-NTA Agarose is the most used tool to purify His-tagged proteins via affinity chromatography.
=== Structure === GsMTx-4 has a polypeptide chain of 35 amino acids with the sequence GCLEF-WWKCN-PNDDK-CCRPK-LKCSK-LFKLC-NFSF, the C-terminus is amidated. The toxin is an amphipathic peptide consisting of a large hydrophobic patch which is surrounded by a ring of six polar lysine residues. These hydrophobic residues enable the toxin to carry an overall charge of +5. The toxin contains three intramolecular disulfide bonds that contribute to the formation of its inhibitor cystine knot (ICK).
A ligament is a small band of dense, white, fibrous elastic tissue. Ligaments connect the ends of bones together in order to form a joint. Most ligaments limit dislocation, and prevent certain movements, such as hyperextension and hyperflexion, which may lead to breaks. An enthesis is the connective tissue that attaches tendons and ligaments to bones. Fascia (from Latin fascia 'band') is a generic term for macroscopic membranous bodily structures. The human skeleton may be divided into two distinct divisions: the axial skeleton, which includes the vertebral column, and the appendicular skeleton.
Sources: en.wikipedia.org
Pemetrexed, sold under the brand name Alimta among others, is a chemotherapy medication for the treatment of pleural mesothelioma and non-small cell lung cancer (NSCLC). It is available as a generic medication.
==== Developing SASO ==== Following the 1968 NUSAS conference in Johannesburg, many of its members attended a July 1968 conference of the University Christian Movement at Stutterheim. There, the black African members decided to hold a December conference to discuss the formation of an independent black student group. The South African Students' Organisation (SASO) was officially launched at a July 1969 conference at the University of the North; there, the group's constitution and basic policy platform were adopted. The group's focus was on the need for contact between centres of black student activity, including through sport, cultural activities, and debating competitions. Though Biko played a substantial role in SASO's creation, he sought a low public profile during its early stages, believing that this would strengthen its second level of leadership, such as his ally Barney Pityana. Nonetheless, he was elected as SASO's first president; Pat Matshaka was elected vice president and Wuila Mashalaba elected secretary. Durban became its de facto headquarters.
Distribution of the Asian citrus psyllid is primarily in tropical and subtropical Asia. It has been reported in all citrus-growing regions in Asia except mainland Japan. The disease has affected crops in China, India, Sri Lanka, Malaysia, Indonesia, Myanmar, the Philippines, Pakistan, Thailand, the Ryukyu Islands, Nepal, Saudi Arabia, and Afghanistan. Areas outside Asia have also reported the disease: Réunion, Mauritius, Brazil, Paraguay, Florida since 2005, and in several municipalities in Mexico since 2009. On 30 March 2012, citrus greening disease was confirmed in a single citrus tree in California. The first report of HLB in Texas occurred on 13 January 2012, from a Valencia sweet orange tree in a commercial orchard in Texas. Prospects are bleak for the ubiquitous backyard citrus orchards of California as residential growers are unlikely to consistently use the pesticides which provide effective control in commercial orchards. The distribution of the African citrus psyllid includes Africa, Madeira, Saudi Arabia, Portugal, and Yemen. This species is sensitive to high temperatures and will not develop at temperatures greater than 25 °C (77 °F). It is a vector of the African strain of huanglongbing (Candidatus Liberibacter africanus), which is sensitive to heat. This strain is reported to occur in Africa, (Burundi, Cameroon, Central African Republic, Comoros, Ethiopia, Kenya, Madagascar, Malawi, Mauritius, Reunion, Rwanda, South Africa, St. Helena [unconfirmed], Swaziland, Tanzania, Zimbabwe), Saudi Arabia, and Yemen. The disease was not reported in the EU as of 2004.
One rack unit (U) is 1.75 inches (44.45 mm) and is used to measure rack-mountable audiovisual, computing and industrial equipment. Rack units are typically denoted without a space between the number of units and the 'U'. Thus, a 4U server enclosure (case) is nominally seven inches (177.8 mm) high, or more precisely, built to occupy a vertical space seven inches high, with sufficient clearance to allow movement of adjacent hardware.
Lisa Sanders in hopes of getting a second opinion, a different diagnosis, or a different treatment. Essentially looking for any route that could lead to a better life for Sadie that doesn't have to hinder her more than her disease hinders her now. Dr. Lisa Sanders put their story out onto her column and awaited for the responses. Many of the responses from the audience agreed with the diagnosis of Rasmussen’s, others suggested that the seizures could be controlled with electro stimulation therapy, and a third group suggested it was a neurologic version of Lyme Disease. She was tested for various diseases under different conditions and one specific test came back strongly positive, resulting in a diagnosis that led to a manageable treatment, and also a responsive neurostimulation device was implanted by a neurosurgeon.
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.
Lyophilized powder is normally kept at minus twenty degrees Celsius or below, in a sealed container, desiccated and away from light. Reconstituted solutions are less stable and are usually refrigerated and used quickly. Repeated temperature cycling should be avoided.