This is a working overview of heptapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-04-17 and is reviewed periodically as new material appears.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
| Property | Value | Notes |
|---|---|---|
| Peptide sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues; tuftsin plus a Pro-Gly-Pro tail |
| Molecular formula | C33H57N11O9 | Commonly reported value for the free peptide |
| Monoisotopic mass | Roughly 751.4 Da | Average molecular mass near 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as a lyophilized solid |
| Solubility class | Freely soluble in water | Also dissolves in saline and other polar solvents |
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
==== Glucose absorption ==== In 1960, the biochemist Robert K. Crane revealed his discovery of the sodium-glucose cotransport as the mechanism for intestinal glucose absorption. This was the very first proposal of a coupling between the fluxes of an ion and a substrate that has been seen as sparking a revolution in biology. This discovery, however, would not have been possible if it were not for the discovery of the molecule glucose's structure and chemical makeup. These discoveries are largely attributed to the German chemist Emil Fischer who received the Nobel Prize in chemistry nearly 60 years earlier.
== Medical uses == Azapirones have shown benefit in general anxiety and augmenting SSRIs in social anxiety and depression. Evidence is not clear for panic disorder and functional gastrointestinal disorders. Tandospirone has also been used to augment antipsychotics in Japan as it improves cognitive and negative symptoms of schizophrenia. Buspirone is being investigated for this purpose as well.
== Acquisition == In June 2013, Amgen offered to buy the shares of Onyx Pharmaceuticals for US$120 per share, sending the shares up by around 30% after the news was announced. Onyx announced on June 30, 2013, that it had rejected the unsolicited proffer from Amgen and its board of directors had subsequently authorized their financial advisers to contact other potential acquisition suitors. However after a series of efforts to secure a higher per-share price from other potential buyers repeatedly failed to materialize, the board reversed course and agreed to Amgen's original terms; the acquisition was formally announced on August 25, 2013.
== Function == FLAP is necessary for the activation of 5-lipoxygenase and therefore for the production of leukotrienes, 5-hydroxyeicosatetraenoic acid, 5-oxo-eicosatetraenoic acid, and specialized pro-resolving mediators of the lipoxin and resolvin classes. It is an integral protein within the nuclear membrane. FLAP is necessary in synthesis of leukotriene, which are lipid mediators of inflammation that is involved in respiratory and cardiovascular diseases. FLAP functions as a membrane anchor for 5-lipooxygenase and as an amine acid-bind protein. How FLAP activates 5-lipooxygenase is not completely understood, but there is a physical interaction between the two. FLAP structure consists of 4 transmembrane alpha helices, but they are found in trimer forming a barrel. The barrel is about 60 Å high and 36 Å wide.
The intersection of fields from the above pair of categories gives rise to fields such as bryogeography, the study of the distribution of mosses. Different parts of plants also give rise to their own subfields, including xylology, carpology (or fructology), and palynology, these being the study of wood, fruit and pollen/spores respectively. Botany also overlaps on the one hand with agriculture, horticulture and silviculture, and on the other hand with medicine and pharmacology, giving rise to fields such as agronomy, horticultural botany, phytopathology, and phytopharmacology.
Sources: en.wikipedia.org
== Honours == Hird jointly won the Brownlow Medal with Michael Voss in 1996, the award for the fairest and best player in the Australian Football League. After his retirement, Hird stated that being a member of the "Brownlow Club" was a privilege. In 1997, the Essendon Football Club named the then-triple best and fairest winner in its Team of the Century on the half-forward flank. In 2002, the Essendon Football Club conducted a fan-voted promotion to find the "Champions of Essendon". Hird was eventually named as the number three player on the all-time list of Essendon players.
Prescription-only medicines (POM), which may be dispensed (sold in the case of a private prescription) by a pharmacist only to those to whom they have been prescribed Pharmacy medicines (P), which may be sold by a pharmacist without a prescription General sales list (GSL) medicines, which may be sold without a prescription in any shop The simple possession of a prescription-only medicine without a prescription is legal unless it is covered by the Misuse of Drugs Act 1971. A patient visits a medical practitioner or dentist, who may prescribe drugs and certain other medical items, such as blood glucose-testing equipment for diabetics. Also, qualified and experienced nurses, paramedics and pharmacists may be independent prescribers. Both may prescribe all POMs (including controlled drugs), but may not prescribe Schedule 1 controlled drugs, and 3 listed controlled drugs for the treatment of addiction; which is similar to doctors, who require a special licence from the Home Office to prescribe schedule 1 drugs. Schedule 1 drugs have little or no medical benefit, hence their limitations on prescribing. District nurses and health visitors have had limited prescribing rights since the mid-1990s; until then, prescriptions for dressings and simple medicines had to be signed by a doctor. Once issued, a prescription is taken by the patient to a pharmacy, which dispenses the medicine. Most prescriptions are NHS prescriptions, subject to a standard charge that is unrelated to what is dispensed.
In 2017, research using a numerical model suggested that a RNA world may have emerged in warm ponds on the early Earth, and that meteorites were a plausible and probable source of the RNA building blocks (ribose and nucleic acids) to these environments. On August 29, 2012, astronomers at Copenhagen University reported the detection of a specific sugar molecule, glycolaldehyde, in a distant star system. The molecule was found around the protostellar binary IRAS 16293-2422, which is located 400 light years from Earth. Because glycolaldehyde is needed to form RNA, this finding suggests that complex organic molecules may form in stellar systems prior to the formation of planets, eventually arriving on young planets early in their formation. Nitriles, key molecular precursors of the RNA World scenario, are among the most abundant chemical families in the universe and have been found in molecular clouds in the center of the Milky Way, protostars of different masses, meteorites and comets, and also in the atmosphere of Titan, the largest moon of Saturn. A study in 2001 shows that nicotinic acid and its precursor, quinolinic acid can be "produced in yields as high as 7% in a six-step nonenzymatic sequence from aspartic acid and dihydroxyacetone phosphate (DHAP). The biosynthesis of ribose phosphate could have produced DHAP and other three carbon compounds. Aspartic acid could have been available from prebiotic synthesis or from the ribozyme synthesis of pyrimidines." This supports that NAD could have originated in the RNA world.
=== Economics === Pregabalin is available as a generic medication in a number of countries, including the United States as of July 2019. In the United States as of July 2019 the wholesale/pharmacy cost for generic pregabalin is $0.17–0.22 per 150-mg capsule. From 2008 until 2018, Pfizer engaged in extensive direct-to-consumer advertising campaigns to promote its branded product Lyrica for fibromyalgia and diabetic nerve pain indications. In January 2016, the company spent a record amount, $24.6 million for a single drug on TV ads, reaching global revenues of $14 billion, more than half in the United States. Up until 2009, Pfizer promoted Lyrica for other uses that had not been approved by medical regulators. For Lyrica and three other drugs, Pfizer was fined a record amount of $2.3 billion by the Department of Justice, after pleading guilty to advertising and branding "with the intent to defraud or mislead". Pfizer illegally promoted the drugs, with doctors "invited to consultant meetings, many in resort locations; attendees expenses were paid; they received a fee just for being there", according to prosecutor Michael Loucks.
Sources: en.wikipedia.org
=== National AI Strategy (2021) === The UK Government's National AI Strategy, was published in September 2021 under the Conservative government of Boris Johnson. It set out a ten-year plan structured around three pillars: investing in the long-term needs of the AI ecosystem; supporting the adoption of AI across all sectors of the economy; and establishing an effective governance framework that ensures AI is safe, ethical, and trustworthy. The strategy identified the UK's world-class universities, research base, and existing technology cluster as competitive advantages to be leveraged.
With their large fore-flippers, eared seals are usually able to prevent the first bite from being secure, but are still weakened and vulnerable to being recaptured. Prey is released after it dies of blood loss, and the shark feeds on the carcass after it floats to the surface. In 1984, Timothy Tricas and John McCosker suggested that white sharks bite seals, release them, and then wait for them to bleed to death before eating based on observations at Dangerous Reef, South Australia. Others have found no evidence for this hypothesis, but the strategy is possibly employed on bull elephant seals. Off South Africa, ambushes on Cape fur seals usually involve the shark leaping or breaching out of the water. To breach, a shark starts at around 20 m (66 ft) below the surface and ascends quickly towards its target while tilting its body vertically. Sharks may breach partially or entirely out of the water at different angles, clearing up to around 3 m (10 ft) when airborne. Missed seals may be chased after; such pursuits involve the prey using its speed and agility to escape as the shark employs various maneuvers to catch them. The longer the chase, the less likely the shark is to succeed. Sharks commonly consume fur seals quickly after they are killed. White sharks in Cape Cod hunt seals in shallow water, relying on the murkiness of the water for concealment and striking them from the sides.
Examination of remains of Homo erectus from Kenya, which are about 1.6 million years old, has revealed signs typical of yaws. The genetic analysis of the yaws causative bacteria—Treponema pallidum pertenue—has led to the conclusion that yaws is the most ancient of the four known Treponema diseases. All other Treponema pallidum subspecies probably evolved from Treponema pallidum pertenue. Yaws is believed to have originated in tropical areas of Africa and spread to other tropical areas of the world via immigration and the slave trade. The latter is likely the way it was introduced to Europe from Africa in the 15th century. The first unambiguous description of yaws was made by the Dutch physician Willem Piso. Yaws was clearly described in 1679 among African slaves by Thomas Sydenham in his epistle on venereal diseases, although he thought that it was the same disease as syphilis. The causative agent of yaws was discovered in 1905 by Aldo Castellani in ulcers of patients from Ceylon. The current English name is believed to be of Carib origin, from "yaya", meaning sore. Towards the end of the Second World War, yaws became widespread in the North of Malaya under Japanese occupation. After the country was liberated, the population was treated for yaws by injections of salvarsan, of which there was a great shortage, so only those with stage 1 were treated.
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.
No peptide with this exact sequence has been identified as an endogenous substance. It is a laboratory-designed analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The Pro-Gly-Pro extension has no known natural source.
Proline introduces conformational constraints that make a peptide less accessible to common peptidases. This is a standard stabilization strategy in peptide design. The added residues also increase the distance between the active tuftsin portion and typical cleavage sites.
Reverse-phase HPLC is the usual method and gives a percentage purity value. Mass spectrometry then confirms the molecular mass. Together they provide a basic identity and purity profile for a lot.