If you have been reading about reversed-phase HPLC and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-01-03. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Quality control for thymosin alpha-1 focuses on identity, purity, and potency. Identity is confirmed by mass spectrometry and amino acid analysis, while purity is assessed by chromatography with limits on related substances and residual solvents. Potency assays may use cell-based immune readouts, but these are not standardized across laboratories. Regulatory status differs by jurisdiction; no product is approved in the United States for clinical use, whereas some other countries register injectable forms for specific indications.
Quantifying thymosin alpha-1 in a sample usually relies on reverse-phase high-performance liquid chromatography. The peptide lacks strong chromophores, so detection often occurs at 214 nm, where the peptide backbone absorbs. Mass spectrometry provides confirmatory identification and can detect sequence variants or truncations. Immunoassays have been used in biological matrices, but they may cross-react with related fragments. For purity assessment, chromatographic peak area gives the main component percentage, while mass accuracy verifies molecular identity.
| 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 |
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.
在信号层面，Tα1可能通过Toll样受体等模式识别受体发挥作用。部分实验显示，它能激活髓样分化因子88依赖的通路，进而促进核因子κB进入细胞核。这导致白细胞介素2、干扰素γ和白细胞介素12等细胞因子的转录增加。这些细胞因子偏向辅助性T细胞1型应答，有助于细胞免疫。然而，具体受体和结合位点尚未完全确定，不同实验模型的结果存在差异。
临床研究将Tα1用于慢性病毒感染、肿瘤辅助治疗和疫苗佐剂等场景。部分试验报告了免疫学指标改善，但临床终点获益在不同研究中并不一致。系统综述指出，研究间在人群、剂量和联合方案上差异较大，难以汇总结论。因此，Tα1的确切临床地位仍属开放问题，需要更多高质量随机对照试验来澄清。其机制研究也需从体外实验向体内模型推进。
胸腺素α1对免疫系统的影响涉及多种细胞类型。研究表明，它可促进未成熟T细胞向成熟T细胞分化，并增强T细胞对抗原刺激的增殖反应。树突状细胞在Tα1存在下表达更高水平的共刺激分子，从而更有效地呈递抗原。此外，自然杀伤细胞的活性也观察到上升。这些效应并非直接杀伤病原体，而是调节宿主免疫应答的强度与方向。
Lyophilized material is generally held at reduced temperature to slow degradation, and storage at minus twenty degrees Celsius or lower is common practice for long-term retention. Short-term working portions are often kept between two and eight degrees Celsius. Once dissolved, the peptide is less stable than the dry powder, and repeated freeze-thaw cycles are associated with loss of material and with aggregate formation. Vials are usually allowed to reach room temperature before opening so that condensation does not introduce moisture, and solutions are protected from light where practical.
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.
Structurally, the conjugated proteins are important in providing stability to cellular components and help intercellular communication which is why glycoproteins are commonly found in cell membranes and extracellular matrices.
== Functions == Individual SHLPs demonstrated different biological effects. SHLP2 and SHLP3 enhanced cell viability and inhibited apoptosis in both NIT-1 and 22Rv1 cells. SHLP2 and SHLP4 promoted cell proliferation in NIT-1 β-cells. SHLP6 significantly increased apoptosis in both NIT-1 and 22Rv1 cells, having an effect opposite of SHLP2 and SHLP3. Moreover, SHLP2 and SHLP3 also induced oxygen consumption rate (OCR) and increased cellular ATP levels, which indicates that SHLP2 and 3 are mitochondrial modulators. Analysis of SHLP and humanin homologs across all vertebrates show that humanin and SHLP6 are well-conserved and subject to natural selection, suggesting that they have a biological function. SHLP4 is conserved but does not appear to be under selection.
Epithelia control the secretion of hormones into the circulatory system, as well as the secretion of sweat, mucus, enzymes, and other products that are delivered by ducts Epithelial membranes include the serous membrane (which lines body cavities), cutaneous membrane (i.e. the skin), and mucous membrane (which lines the interior of hollow organs). Other functions of epithelial cells include diffusion, filtration, secretion, selective absorption, and transcellular transport.
This is a methylation reaction in which glycocyamine is converted to creatine. The methyl group comes from the cofactor, S-adenosyl methionine (SAM), which loses its methyl group and becomes S-adenosyl-L-homocysteine (SAH). This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is S-adenosyl-L-methionine:N-guanidinoacetate methyltransferase. Other names in common use include GA methylpherase, guanidinoacetate methyltransferase, guanidinoacetate transmethylase, methionine-guanidinoacetic transmethylase, and guanidoacetate methyltransferase. It participates in the metabolism of amino acids. Defects in the gene which encodes this protein have been implicated in neurologic syndromes and muscular hypotonia, probably due to creatine deficiency and accumulation of guanidinoacetate in the brain of affected individuals. Two transcript variants encoding different isoforms have been described for this gene.
=== The 1990s === The success of Cycles led to the release of 1991's Brotherhood, also on Capitol. The group members grew their hair back out, wore denim and leather, and attempted to revive their biker image of the early 1970s. In spite of the makeover and strong material led by Simmons' now trademark "Dangerous" (featured in the Brian Bosworth biker film Stone Cold), Brotherhood was unsuccessful, in part due to a lack of support from Capitol Records, who dropped the group from their roster by the end of 1991. The accompanying tour (the 1989 lineup minus Bumpus), which also featured Joe Walsh on the bill, ranked among the ten least profitable tours of the 1991 summer season by the North American Concert Promoters Association, and after losing the Capitol deal, the group was inactive by the end of '91, its future uncertain. The 1987 Doobie Brothers alumni band reunited on October 17 and 19, 1992, at the Concord Pavilion in Concord, California to perform benefit shows for LaKind's children. LaKind, terminally ill with colon cancer, joined the group on percussion for a few numbers. The concerts were recorded and subsequently broadcast on the Superstars in Concert radio series accompanied by a plea for contributions to the LaKind family fund. LaKind died on December 24, 1992, at the age of 47. Another brief hiatus followed during which Simmons collaborated with bassist and songwriter John Cowan (ex-New Grass Revival), Rusty Young (of Poco) and Bill Lloyd (of Foster & Lloyd) on an unreleased project called Four Wheel Drive.
Sources: en.wikipedia.org
== Medical uses == Cilostazol is approved for the treatment of intermittent claudication in the United States and United Kingdom. If no improvement is seen after 3 months, stopping the medication is reasonable. Cilostazol is also used for secondary stroke prevention, though to date no regulatory body has approved it specifically for that indication.
Bacterial and mitochondrial N-formyl peptides such as FMLP – pro-inflammatory (though possibly less physiologically significant than lipid-derived ligands); Hp(2–20), from Helicobacter pylori – pro-inflammatory; HIV-1-derived peptides: T21/DP107 and N36 (from gp41), F peptide (from gp120), and V3 peptide (from the MN strain) – unknown effects; CCL23β (amino acids 22–137), a splice variant of CCL23, and SHAAGtide, a proteolytic product – pro-inflammatory; Annexin A1-derived peptides (Ac2–26 and Ac9–25) – dose-dependent; anti-inflammatory at low concentrations, pro-inflammatory at high concentrations; Amyloid β(1–42) and PrP(106–126) (from prion protein) – pro-inflammatory, suggesting roles in Alzheimer's disease, Parkinson's disease, Huntington's disease, and prion diseases such as Creutzfeldt–Jakob disease and Kuru; Humanin, a neuroprotective peptide – anti-inflammatory, counteracting amyloid-induced inflammation; Cleaved fragments of UPARAP (uPAR): D2D3(88–274) and uPAR(84–95) – pro-inflammatory; Antimicrobial peptides: LL-37 and CRAMP (human/rat cathelicidins), Pleurocidins (from fish), and Temporin A (frog-derived) – pro-inflammatory; Pituitary adenylate cyclase-activating polypeptide 27 – pro-inflammatory; Long-chain ceramides (C14–C20) – bind FPR2 in beige and brown adipocytes to inhibit thermogenesis.
New company developments included new instrumentation for robotics and detection of DNA fragments using the company's fluorescent labelling. Also in 1990, the U.S. government approved financing to support the Human Genome Project. Dr. James D. Watson, who founded the consortium, forecast that the project could be completed in 15 years from its 1990 starting date, at a cost of cost US$3 billion. Over the next couple years, Japan began a project to sequence the rice genome, and other laboratories initiated programs to sequence the mouse, fruit fly, and yeast genomes. In 1991, Applied sales revenue grew slightly, to almost $164 million, with consumables and service contracts up by 24% to account for 47% of total sales, and DNA sequencer and DNA synthesis instruments having record sales. Forty-five new consumable products and six new instruments were introduced. In 1992, sales revenue grew by more than 11% to over $182 million, with Europe representing 25% of revenue, and Asia and the Pacific Rim accounting for 26%. The company formed a new subsidiary, Lynx Therapeutics, Inc., to focus on antisense DNA research in the area of therapeutics for chronic myelogenous leukemia, melanoma, colorectal cancer, and AIDS.
== Market withdrawal == Bayer announced that it ceased the production of lepirudin (Refludan) on May 31, 2012. At the time of the announcement, the company expected that supply from wholesalers was going to be depleted by mid-2013.
Lt. Col. J. H. Fuller (18 April 1909 – 1 April 1911) Maj. Gordon Vallancy Drury (1 April 1911 – 28 January 1913) Maj. Gen. Sir Alfred Hamilton Mackenzie Edwards (28 January 1913 – 23 January 1923) Col. Algernon Essex Capell (1 February 1923 – 11 February 1926) Alfred James Tomlinson (12 February 1926 – 12 May 1926; acting) Col. George Stops (13 May 1926 – 14 February 1933) Brig. John Sidney Morris (15 February 1933 – 24 April 1945) Brig. John Ellis "Jack" Ross (24 April 1945 – 6 December 1950) Col. James Appleby (7 December 1950 – 2 June 1954) Col. Arthur Selwyn Hickman (3 June 1954 – 5 November 1955) Col. Harold Jackson (6 November 1955 – 12 March 1958) Basil Gordon Spurling (13 March 1958 – 25 April 1963) Frank Eric Barfoot (26 April 1963 – 2 January 1968) James Spink (3 January 1968 – 26 June 1970) Sydney Frederick Samuel Bristow (27 June 1970 – 6 February 1974) Peter Dennis Wray Richard Sherren (7 February 1974 – 6 February 1978) Peter Kevin Allum (7 February 1978 – 6 February 1982)
Sources: en.wikipedia.org
=== Controlling neuron activity states === The Na+-K+ pump has been shown to control and set the intrinsic activity mode of cerebellar Purkinje neurons, accessory olfactory bulb mitral cells and probably other neuron types. This suggests that the pump might not simply be a homeostatic, "housekeeping" molecule for ionic gradients, but could be a computation element in the cerebellum and the brain. Indeed, a mutation in the Na+-K+ pump causes rapid onset dystonia-parkinsonism, which has symptoms to indicate that it is a pathology of cerebellar computation. Furthermore, an ouabain block of Na+-K+ pumps in the cerebellum of a live mouse results in it displaying ataxia and dystonia. Alcohol inhibits sodium–potassium pumps in the cerebellum and this is likely how it corrupts cerebellar computation and body coordination. The distribution of the Na+-K+ pump on myelinated axons in the human brain has been demonstrated to be along the internodal axolemma, and not within the nodal axolemma as previously thought. The Na+-K+ pump disfunction has been tied to various diseases, including epilepsy and brain malformations.
PAH is definitively diagnosed with a right heart catheterization showing a mean pulmonary arterial pressure greater than 20 mmHg at rest, with a pulmonary vascular resistance being 3 Woods Units or greater (indicative of pulmonary hypertension in the pre-capillary vasculature; the arteries and arterioles), and a pulmonary artery wedge pressure being less than 15 mmHg (excluding post-capillary pulmonary hypertension; elevated pressures distal to the pulmonary capillary bed which may be seen in left heart disease). Inhaled nitric oxide (a potent vasodilator) or other vasodilators (adenosine, prostaglandin I2) are infused during the right heart catheterization to see if the PAH is responsive to vasodilators which may guide treatment decisions (use of calcium channel blockers). Various clinical tests, such as the 6-minute walk test (the distance a person is able to walk in 6 minutes) are used prognostically as well as to assess response to treatment.
Homocysteine is biosynthesized naturally via a multi-step process. First, methionine receives an adenosine group from ATP, a reaction catalyzed by S-adenosyl-methionine synthetase, to give S-adenosyl methionine (SAM). SAM is a widely used source of methyl radicals and a cofactor for radical SAM enzymes. Transfer of the methyl group to an acceptor molecule results in the formation of S-adenosyl-homocysteine. Hydrolysis of this thioether gives L-homocysteine. L-Homocysteine reacts with tetrahydrofolate (THF) to give L-methionine.
Towards this end it sacrifices all, including the interests of the most revolutionary sections of the working class.” Here the CLP is referring to Lenin’s statement that the super-profits from the exploitation of the colonial peoples are used to bribe a sector of the working class in the imperialist country and turn this sector into an ally of the ruling class against the non-bribed sector of the working class. And further, "... the increasing economic crisis has forced the so-called "center” to the right and with it the CPUSA has moved to the right as well.”
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.
Reverse-phase HPLC with ultraviolet detection at 214 nm is common. Mass spectrometry is used to confirm molecular identity and detect modifications. Immunoassays exist but may not distinguish the intact peptide from fragments.