This is a working overview of tuftsin, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-01-03 and is reviewed periodically as new material appears.
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Stabilized analog of tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Monoisotopic mass about 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in common polar solvents |
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.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
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.
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.
=== James: The Boss's Son === First aired: Online James bullies fellow co-worker Sean. The only problem is that James is the boss's son. Ben Lagman submits James three times in the first round, but James survives the second round, despite taking quite a beating. This was Ben Lagman's first and, so far, only appearance in the series. The episode did not air in regular chronology and is not available on the Bully Beatdown website like most other episodes. It has been leaked on to the internet and it is unknown why the episode was not aired in the regular time slot. This episode has aired, late nights on MTV2.
=== Phosphotungstic acid === Phosphotungstic acid is a common negative stain for viruses, nerves, polysaccharides, and other biological tissue materials. It is mostly used in a .5-2% ph form making it neutral and is paired with water to make an aqueous solution. Phosphotungstic acid is filled with electron dense matter that stains the background surrounding the specimen dark and the specimen itself light. This process is not the normal positive technique for staining where the specimen is dark and the background remains light.
== Pathophysiology == Myophosphorylase is involved in the breakdown of glycogen to glucose-1-phosphate for use in muscle. The enzyme removes 1,4 glycosyl residues from the outer branches of glycogen and adds inorganic phosphate to form glucose-1-phosphate. Ordinarily, the removal of 1,4 glycosyl residues by myophosphorylase leads to the formation of glucose-1-phosphate during glycogen breakdown and the polar, phosphorylated glucose cannot leave the cell membrane and so is marked for intracellular catabolism. In McArdle's disease, deficiency of myophosphorylase leads to the accumulation of intramuscular glycogen and a lack of glucose-1-phosphate for cellular fuel. Myophosphorylase comes in two forms: form 'a' is phosphorylated by phosphorylase kinase, form 'b' is not phosphorylated. Form 'a' is de-phosphorylated into form 'b' by the enzyme phosphoprotein phosphatase, which is activated by elevated insulin. Both forms have two conformational states: active (R or relaxed) and inactive (T or tense). When either form 'a' or 'b' is in the active state, then the enzyme converts glycogen into glucose-1-phosphate. Myophosphorylase-b is allosterically activated by elevated AMP within the cell, and allosterically inactivated by elevated ATP and/or glucose-6-phosphate. Myophosphorylase-a is active unless allosterically inactivated by elevated glucose within the cell. In this way, myophosphorylase-a is the more active of the two forms as it will continue to convert glycogen into glucose-1-phosphate even with high levels of glycogen-6-phosphate and ATP.
In other countries, such as Egypt, it is legal to use and purchase tobacco products regardless of age. Germany raised the purchase age from 16 to 18 on September 1, 2007. Some police departments in the United States occasionally send an underaged teenager into a store where cigarettes are sold, and have the teen attempt to purchase cigarettes, with their own or no ID. If the vendor then completes the sale, the store is issued a fine. Similar enforcement practices are regularly performed by Trading Standards officers in the UK, and by equivalents in Israel and the Republic of Ireland.
== Biochemistry == DTPA is more effective than EDTA to deactivate redox-active metal ions such as Fe(II)/(III), Mn(II)/(IV) and Cu(I)/(II) perpetuating oxidative damages induced in cells by superoxide and hydrogen peroxide. DTPA is also used in bioassays involving redox-active metal ions.
Sources: en.wikipedia.org
, then humanity's energy consumption will exceed the incident solar power (1.742×1017 W) after 240 years, the total power of the Sun (3.826×1026 W) after 800 years, and that of the Galaxy (7.29×1036 W) after 1,500 years. Based on this calculation, Zuckerman estimates the number of civilizations that could exist in our galaxy at 10,000. Kardashev concludes that the current exponential growth is a transitional phase in the development of a civilization, and that it is inevitably limited by natural factors. In fact, he believes that the required mass and energy will continue to grow exponentially for another 1,000 years. Civilization is thus defined by an exponential rate of increase. Humanity as a model for thinking about the development of extraterrestrial civilizations has its limitations, which can be truly overcome by a multidisciplinary approach according to the work of Kathryn Denning.
The plasmon resonance displayed by nanoparticles, gold particles are most often used as an example, can be altered using the interfacial layer. When either anionic or cationic ligands bound to a nanoparticle made of gold for example are increased in length, the wavelength of the plasmon resonance will shift to red. An example of another effect, that has recently been observed by Amendola et al. on small gold nanoparticles, of 10 nm or less, is that dense monolayers that consist of certain specific short chain ligands tend to dampen the surface plasmon resonance effects. Plasmon resonance can be used to analyze the surfactants of the nanoparticle. This principle is based on the so-called Fröhlich condition which states that the refractive index of the surrounding medium of a nanoparticle can be used to tune or alter the frequency of the surface plasmon resonance. The equation that relates both properties is as follows:
=== Legal definition === As of 23 November 2009, the Scotch Whisky Regulations 2009 (SWR) define and regulate the production, labelling, packaging as well as advertising of Scotch whisky in the United Kingdom. They replace previous regulations that focused solely on production, including the Scotch Whisky Act 1988. Since the previous act focused primarily on production standards, it was repealed and superseded by the 2009 Regulations. The SWR includes broader definitions and requirements for the crafting, bottling, labelling, branding, and selling of "Scotch Whisky". International trade agreements have the effect of making some provisions of the SWR apply in various other countries as well as in the UK. The SWR defines "Scotch whisky" as whisky that:
==== Dunwall ==== Antonov was the principal designer of the city of Dunwall, Dishonored's steampunk dystopian setting described as an "oily" labyrinth of brickwork buildings. The city, whose economy is centered around the whaling industry, is governed by an authoritarian monarchist regime filled with officials too "callous" to deal with its residents' problems. During the events of the game, Dunwall is experiencing a plague virus which originated from its overwhelming rat population. It has significant wealth inequality, and the plague has trapped its lower class inside the city, "condemned to die by either an infection in the body or a knife in the heart", Levi Winslow writes for Kotaku. The city features a mix of Victorian and Gothic architecture, and was inspired by British cities, mainly London and Edinburgh, as they were from the mid-1800s to 1930. Antonov stated that that Britain is "both exotic and familiar to Americans and to Europeans, so it was just about perfect".
Sources: en.wikipedia.org
=== Regional organizations === In regional organizations like the European Union, African Union, Indian Ocean Rim Association, NATO, ASEAN, Mercosur, Andean Community and the Organization of American States, there are restrictions on membership due to factors such as geography or political regimes. To enter the European Union (EU), the states require different criteria; member states need to be European, liberal-democratic political system, and be a capitalist economy. The oldest regional organization is the Central Commission for Navigation on the Rhine, created in 1815 by the Congress of Vienna.
Halliwell B; Gutteridge JM (1984). "Oxygen toxicity, oxygen radicals, transition metals and disease". Biochemical Journal. 219 (1): 1–14. doi:10.1042/bj2190001. PMC 1153442. PMID 6326753. Murphy MP, Bayir H, Belousov V, Chang CJ, Davies KJ, Davies MJ, Dick TP, Finkel T, Forman HJ, Gems D, Janssen-Heininger Y, Kagan VE, Kalyanaraman B, Larsson NG, Mile GL, Nyström T, Poulsen HE, Radi R, Remmen HV, Schumacker PT, Thornalley PJ, Toyokuni S, Winterbourn CC, Yin H, Halliwell B. (2022) Guidelines for measuring reactive oxygen species and oxidative damage in cells and in vivo. Nature Metabolism 4, 651–662. Research articles
The structure of tRNA can be decomposed into its primary structure, its secondary structure (usually visualized as the cloverleaf structure), and its tertiary structure (all tRNAs have a similar L-shaped 3D structure that allows them to fit into the P and A sites of the ribosome). The cloverleaf structure becomes the 3D L-shaped structure through coaxial stacking of the helices, which is a common RNA tertiary structure motif. The lengths of each arm, as well as the loop 'diameter', in a tRNA molecule vary from species to species. The tRNA structure consists of the following:
Some PCR fingerprint methods have high discriminative power and can be used to identify genetic relationships between individuals, such as parent-child or between siblings, and are used in paternity testing (Fig. 4). This technique may also be used to determine evolutionary relationships among organisms when certain molecular clocks are used (i.e. the 16S rRNA and recA genes of microorganisms).
At the end of the 1950s, the USSR constructed the first satellite—Sputnik 1, which marked the beginning of the Space Race—a competition to achieve superior spaceflight capability with the United States. This was followed by other successful satellites, most notably Sputnik 5, where test dogs were sent to space. On 12 April 1961, the USSR launched Vostok 1, which carried Yuri Gagarin, making him the first human to ever be launched into space and complete a space journey. The first plans for space shuttles and orbital stations were drawn up in Soviet design offices, but personal disputes between designers and management prevented their development. In terms of the Luna program, the USSR only had automated spacecraft launches with no crewed spacecraft. The N1—a Super heavy-lift launch vehicle intended to match the American Saturn V for a Soviet crewed moon landing—failed all four of its test launches, and the 'Moon' part of Space Race was won by the Americans. The Soviet public's reaction to the American moon-landing was mixed. The Soviet government limited the release of information about it, which affected the reaction. A portion of the populace did not give it attention, and another portion was angered. In the 1970s, specific proposals for the design of a space shuttle emerged, but shortcomings, especially in the electronics industry (rapid overheating of electronics), postponed it till the end of the 1980s. The first shuttle, the Buran, flew in 1988, but without a human crew. Another, Ptichka, endured prolonged construction and was canceled in 1991.
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.
It was developed in Russia, at the Institute of Molecular Genetics of the Russian Academy of Sciences, during the 1990s. Most published research originates from Russian institutions. Independent international replication remains limited.
Tuftsin is a natural tetrapeptide with the sequence Thr-Lys-Pro-Arg that participates in immune signaling. Selank extends that sequence with Pro-Gly-Pro at the C-terminus. The added residues are linked to greater resistance to enzymatic breakdown.
Selank is a synthetic seven-amino-acid peptide modeled on tuftsin, a fragment of the immunoglobulin G heavy chain. It was designed in Russia to combine anxiolytic and immunomodulatory properties in one molecule.