Everything below concerns Heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-04-07. Where a claim depends on a specific study, the study is described rather than over-claimed.
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Calculated for the free peptide |
| Molecular weight | About 751.9 g/mol | Derived from the sequence |
| Appearance | White to off-white powder | Typical lyophilised form |
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.
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.
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For example, the stepwise liquid-phase synthesis of the dipeptide Z-L-Phg-L-Val-OMe yields the LL-product with 81-84% which is free from racemic DL dipeptide, using From N-protected Z-L-α-phenylglycine (with the benzyloxycarbonyl group, Z group) and L-valine methyl ester with the coupling reagent DIC and the additive ethyl cyanohydroxyiminoacetate. More recently, a variety of derivatives of ethyl cyanohydroxyiminoacetate (Oxyma) have been developed as acylation reagents, such as Fmoc-oxyma for the transfer of the fluorenylmethoxycarbonyl protective group
As the number of known specimens increased, scientists began to analyze the variation between individuals and discovered what appeared to be two distinct body types, or morphs, similar to some other theropod species. As one of these morphs was more solidly built, it was termed the 'robust' morph while the other was termed 'gracile'. Several morphological differences associated with the two morphs were used to analyze sexual dimorphism in T. rex, with the 'robust' morph usually suggested to be female. For example, the pelvis of several 'robust' specimens seemed to be wider, perhaps to allow the passage of eggs. It was also thought that the 'robust' morphology correlated with a reduced chevron on the first tail vertebra, also ostensibly to allow eggs to pass out of the reproductive tract, as had been erroneously reported for crocodiles. In recent years, evidence for sexual dimorphism has been weakened. A 2005 study reported that previous claims of sexual dimorphism in crocodile chevron anatomy were in error, casting doubt on the existence of similar dimorphism between T. rex sexes. A full-sized chevron was discovered on the first tail vertebra of Sue, an extremely robust individual, indicating that this feature could not be used to differentiate the two morphs anyway. As T. rex specimens have been found from Saskatchewan to New Mexico, differences between individuals may be indicative of geographic variation rather than sexual dimorphism. The differences could also be age-related, with 'robust' individuals being older animals.
== Contraindications == Contraindications are severe respiratory or liver impairment and acute alcoholism. There are limited accounts of cross-reactivity with opioids, but there is a possibility. Serious central nervous system (CNS) and respiratory depression may also occur with concurrent use of CNS depressants, ingesting alcohol, or other CNS-depressing factors while on buprenorphine/naloxone.
Sources: en.wikipedia.org
Police issue a "Gang Conflict Warrant" in Levin following a spate of local gang violence and shootings. 22 August – Dairy cooperative Fonterra sells its Mainland, Anchor brands, and processing operations in Australia and Sri Lanka to French dairy company Lactalis for NZ$3.845 billion. 23 August — NZ Post suspends several postal services to the United States and its unincorporated territories in response to the Trump Administration's new 15 percent tariff rates. 25 August – The murder trial of a man accused of perpetrating the Loafers Lodge fire in May 2023, which claimed five lives, commences at the Wellington High Court. 27 August — Economic Growth Minister Nicola Willis announces that the Government would amend legislation with the goal of breaking the country's supermarket duopoly. 28 August: Associate Justice Minister Nicole McKee announces the Government will amend alcohol legislation to make it harder for people to block liquor licenses and to introduce one-off special trading hours for pubs and clubs hosting major sport and cultural events. NZ Post introduces a new business parcel service to the United States in response to the Trump Administration's 15 percent tariff rate. 160 Stuff journalists affiliated with the E tū union strike in Auckland, Hamilton, Wellington and Christchurch to protest work and pay conditions. 29 August — Neil Quigley resigns as chairman of the Reserve Bank of New Zealand's board.
== In stress == Stress granules are composed of protein and RNA, and form from pools of mRNAs that have not started translation as a result of environmental conditions including oxidative stress, temperature, toxins, and osmotic pressure. Stress granules also contain translation initiation factors, RNA binding proteins (which account for 50% of the granule's components), and non-RNA binding proteins. They are formed via protein-protein interactions between mRNA binding proteins and are influenced by protein methylation or phosphorylation. They contain a “core” with high concentrations of proteins and mRNA and a less-concentrated outer region. Stress granules are dynamic in structure, and can dock and exchange with p-bodies or the cytoplasm. They can also perform fusion and fission in the cytoplasm.
By the 1820s, the different Nonconformists, including Wesleyan Methodists, Baptists, Congregationalists and Unitarians, had formed the Committee of Dissenting Deputies and agitated for repeal of the highly restrictive Test and Corporation Acts. These Acts excluded Nonconformists from holding civil or military office or attending Oxford or Cambridge, compelling them to set up their own Dissenting Academies privately. The Tories tended to be in favour of these Acts and so the Nonconformist cause was linked closely to the Whigs, who advocated civil and religious liberty. After the Test and Corporation Acts were repealed in 1828, all the Nonconformists elected to Parliament were Liberals. Nonconformists were angered by the Education Act 1902, which integrated Church of England denominational schools into the state system and provided for their support from taxes. John Clifford formed the National Passive Resistance Committee and by 1906 over 170 Nonconformists had gone to prison for refusing to pay school taxes. They included 60 Primitive Methodists, 48 Baptists, 40 Congregationalists and 15 Wesleyan Methodists. The political strength of Dissent faded sharply after 1920 with the secularisation of British society in the 20th century. The rise of the Labour Party reduced the Liberal Party strongholds into the nonconformist and remote "Celtic Fringe", where the party survived by an emphasis on localism and historic religious identity, thereby neutralising much of the class pressure on behalf of the Labour movement.
== Biology == Unlike the other amino acids, no free pool of selenocysteine exists in the cell. Its high reactivity would cause damage to cells. Instead, cells store selenium in the less reactive oxidized form, selenocystine, or in methylated form, selenomethionine.
== Function == The UBC9 protein encoded by the UBE2I gene constitutes a core machinery in the cell's sumoylation pathway. Sumoylation is a process in which a Small Ubiquitin-like MOdifier (SUMO) is covalently attached to other proteins in order to modify their behaviour. For example, sumoylation may affect a protein's localization in the cell, its ability to interact with other proteins or DNA. UBC9 performs the third step in the sumoylation life cycle: the conjugation step. When SUMO protein precursors are first expressed, they first undergo a maturation step in which the four C-terminal amino acids are removed, revealing a di-glycine motif. In a second step, an E1 activating complex binds to SUMO at its di-glycine and passes it on to the E2 protein Ubc9, where it forms a thioester bond with a cysteine residue within Ubc9's catalytic pocket. The loaded Ubc9 is now ready to perform the sumoylation of its various target proteins (also called substrates). It recognizes a particular motif of amino acid residues in these substrates: A large hydrophobic residue, followed by a lysine, followed by a spacer, followed by an acidic residue. This motif is usually described in shorthand as ΨKxD/E. The central lysine within the substrate's recognition motif is inserted into the catalytic pocket. There the carboxyl terminus of SUMO's di-glycine forms a peptide bond with the ε-amino group of the lysine. This process can be assisted by an E3 ligase protein. The sumoylation process is reversible.
Sources: en.wikipedia.org
a very clear sense of his rigid code of honour is plain, and a conviction that not only unity, peace and happiness in South Africa, but also the peace of Europe would be endangered if he told the truth. He believed that, as he had given Rhodes his word not to divulge certain private conversations, he had to abide by that, while at the same time he was convinced that it would be very damaging to Britain if he said anything to the parliamentary committee to show the close involvement of Sir Hercules Robinson and Joseph Chamberlain in their disreputable encouragement of those plotting an uprising in Johannesburg. Finally, Cousins states that
As with cocaine in Coca-Cola, lithium was widely marketed as one of several patent medicine products popular in the late 19th and early 20th centuries and was claimed to be included in many drinks including lithia water and 7 Up. Charles Leiper Grigg, who launched his St. Louis-based company The Howdy Corporation, invented a formula for a lemon-lime soft drink in 1920. The product, at one point named "7Up Lithiated Lemon Soda", was launched two weeks before the Wall Street Crash of 1929. It claimed to contain the mood stabilizer lithium citrate, and was one of many patent medicine products popular in the late-19th and early-20th centuries. All references to lithium were removed in 1937 after it became clear that 7Up contains no lithium. Many sources written by scientists (instead of historians) incorrectly report that 7 Up was forced to remove lithium in 1948, with an FDA action that supposedly banned lithium from beverages. Despite the supposed ban, in 1950, the Painesville Telegraph still carried an advertisement for a lithiated lemon beverage.
== Medical uses == Both corticotropin and tetracosactide have been used for diagnostic purposes to determine adrenocortical insufficiency, particularly in Addison's disease, via the ACTH stimulation test. However, as of 2015 the US label for corticotropin does not include diagnostic use. Both corticotropin and tetracosactide have been used for therapeutic purposes. In the US the tetracosactide label is limited to diagnosis but the UK label provides for therapeutic uses. In the US corticotropin is used to treat epileptic spasms in infants, acute exacerbations of multiple sclerosis in adults; acute episodes of psoriatic arthritis and rheumatoid arthritis and ankylosing spondylitis; in acute exacerbations or as maintenance therapy for collagen disorders like systemic lupus erythematosus and systemic dermatomyositis; for skin conditions like severe erythema multiforme and Stevens–Johnson syndrome; for serum sickness; for severe acute and chronic allergic and inflammatory processes involving the eye such as keratitis, iritis and iridocyclitis, diffuse posterior uveitis, choroiditis, optic neuritis, chorioretinitis, and anterior segment inflammation; sarcoidosis in the lungs; and to treat edema in certain nephrotic syndromes. In the UK tetracosactide is used for short-term therapy in conditions for which glucocorticoids are usually used but for some reason should not be; some uses include use for people who do not respond to glucocorticoids or cannot tolerate them who have ulcerative colitis, Crohn's disease, juvenile rheumatoid arthritis, rheumatoid arthritis, or osteoarthrosis.
Kozak consensus sequence Also simply Kozak sequence. A highly conserved nucleic acid sequence motif which functions as the recognition site for the initiation of translation in most eukaryotic messenger RNAs, generally a sequence of 10 bases immediately surrounding and inclusive of the start codon: GCCRCCAUGG. As the pre-initiation complex scans the transcript, recognition of this sequence (or a close variant) causes the complex to commit to full ribosome assembly and the start of translation. The Kozak sequence is distinct from other recognition sequences relevant to translation such as ribosome binding sites and internal ribosome entry sites.
Russia launched about 85 to 100 missiles at a number of Ukrainian cities. The strategic bombing campaign caused severe shortages of electricity and water at multiple cities. According to the Ukrainian Air Force some 77 of 96 Russian missiles were shot down. A Pentagon official claimed the Russian plan was to exhaust the Ukrainian air defences. At one stage some 50 missiles were in combat "within minutes" near the Polish border. A missile crossed over the Ukrainian-Polish border and struck the village of Przewodów, killing two civilians. Top leaders in Poland held an emergency meeting. Initial assessments by the United States found that the missile was likely to have been an air defence missile fired by Ukrainian forces at an incoming Russian missile. According to Ukraine's Operational Command South, Ukrainian rocket and artillery units attacked Russian positions on the left bank of the Dnipro River and in the area of the Kinburn Spit.
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, commonly written as TKPRPGP. It shares the first four residues with tuftsin and carries three prolines in the chain. The proline-rich tail is the main structural feature that separates it from the parent tetrapeptide.
Selank is a synthetic analogue built on the tuftsin tetrapeptide Thr-Lys-Pro-Arg. Extra proline residues were added to the C-terminus during design work. That modification is intended to make the peptide less vulnerable to rapid enzymatic degradation.
Transliteration from Russian produces variant spellings such as Selanc. Many suppliers avoid the trade-style name entirely and list the peptide sequence. Comparing sequences rather than names is the reliable way to confirm two entries describe the same molecule.
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.