If you have been reading about Tuftsin analog 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.
Last reviewed on 2025-10-31. Where a claim depends on a specific study, the study is described rather than over-claimed.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
Reversed-phase high-performance liquid chromatography is the standard technique for estimating peptide purity. The result is a peak-area percentage, which describes how much of the detected material elutes as the main peak in one run. Mass spectrometry confirms the molecular mass and can reveal truncated, adducted, or otherwise modified species. Amino acid analysis or tandem mass spectrometry can address sequence fidelity when identity is in doubt. None of these measurements, taken alone, establishes that a sample is fit for any specific purpose.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue with a C-terminal Pro-Gly-Pro tail |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Abbreviated TKPRPGP in most catalogues |
| Molecular mass | About 752 Da | Value for the free peptide |
| Solubility | Freely soluble in water | Aqueous solutions are kept cold and used promptly |
| Typical storage | -20 °C, dry, protected from light | Applies to the lyophilised powder before reconstitution |
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.
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
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 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.
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.
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.
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.
== Disease relevance == E3 ubiquitin ligases regulate homeostasis, cell cycle, and DNA repair pathways, and as a result, a number of these proteins are involved in a variety of cancers, including famously MDM2, BRCA1, and Von Hippel-Lindau tumor suppressor. For example, a mutation of MDM2 has been found in stomach cancer, renal cell carcinoma, and liver cancer (amongst others) to deregulate MDM2 concentrations by increasing its promoter's affinity for the Sp1 transcription factor, causing increased transcription of MDM2 mRNA. Several proteomics-based experimental techniques are available for identifying E3 ubiquitin ligase-substrate pairs, such as proximity-dependent biotin identification (BioID), ubiquitin ligase-substrate trapping, and tandem ubiquitin-binding entities (TUBEs).
is known as the Lamb vector. For the special case of an incompressible flow, the pressure constrains the flow so that the volume of fluid elements is constant: isochoric flow resulting in a solenoidal velocity field with
Freeze branding (sometimes called CryoBranding and the resulting brands, trichoglyphs) is a technique involving a cryogenic coolant instead of heat to produce permanent marks on a variety of animals. The coolant is used to lower the temperature of a branding iron such that its application to shaved skin will permanently alter hair follicles. The intense cold destroys the pigmentation apparatus in the animal's hair follicles, leaving all subsequent hair growth without color. This creates a high-contrast, permanent mark in the shape of the branding iron's head. A longer application of the cold iron can also permanently remove hair and is used on white or pale animals. In these cases, the loss of hair leaves a patch of hairless skin in the shape of the brand. The technique is most commonly used as an identification mark for ownership, although it finds application in biological studies of wild animals as well. Freeze branding is most often used on mammalian livestock with smooth coats such as cattle, donkeys and horses although it has been used successfully on a wide variety of other mammals, as well as frogs, newts, snakes, fish and even crabs. Freeze branding is often seen as a more ethical alternative to traditional hot branding, so much so that experts have called for the prohibition of hot branding in favor of the cryogenic technique. Hot branding involves the use of an iron stamp heated to around 500 ºC (930 ºF), a temperature sufficient to destroy all three layers of an animal's skin and leave a permanent scar.
=== Medications === Medications for PMOS include metformin and oral contraceptives. Metformin is a medication commonly used in type 2 diabetes, and is used frequently off-label in the management of PMOS. It is recommended for those with a BMI over 25 to treat insulin resistance and normalise lipid profiles, and can also be considered for the treatment of irregular periods in adolescents and for those with a BMI under 25. Metformin is associated with several side effects, including abdominal pain, metallic taste in the mouth, diarrhoea and vomiting. It can also be used to help women get pregnant, but it is not the most effective drug for it. Combined oral contraceptives (COCs) can be used to reduce the symptoms of hirsutism and regulate menstrual periods. They increase sex hormone binding globulin production, and reduce levels of androgens. A regular cycle reduces the risk of endometrial cancer. Contraceptive pills with only progestogens can be used to improve menstrual regularity, but not for symptoms of androgen excess. Antiandrogens such as finasteride and flutamide do not show advantages over COCs for treating hirsutism, but can be an option for people for whom COCs are contraindicated or who do not tolerate them. It may take six to twelve months for COCs to be effective for hirsutism. For the treatment of androgenic alopecia, a combination of antiandrogens and combined oral contraceptives can be tried, but it is difficult to treat. GLP-1 receptor agonists, such as liraglutide and semaglutide, may be more effective than metformin alone at metabolic improvements.
Sources: en.wikipedia.org
=== 2000 census === As of the census of 2000, there were 2,975 people, 1,116 households, and 785 families living in the city. The population density was 1,431.1 inhabitants per square mile (552.6/km2). There were 1,145 housing units at an average density of 550.8 units per square mile (212.7 units/km2). The racial makeup of the city was 98.39% White, 0.20% African American, 0.07% Native American, 0.20% Asian, 0.71% from other races, and 0.44% from two or more races. Hispanic or Latino of any race were 1.34% of the population. There were 1,116 households, out of which 36.9% had children under the age of 18 living with them, 58.1% were married couples living together, 8.6% had a female householder with no husband present, and 29.6% were non-families. 26.3% of all households were made up of individuals, and 16.6% had someone living alone who was 65 years of age or older. The average household size was 2.56 and the average family size was 3.11. In the city, the population was spread out, with 27.8% under the age of 18, 7.2% from 18 to 24, 26.6% from 25 to 44, 17.4% from 45 to 64, and 21.0% who were 65 years of age or older. The median age was 37 years. For every 100 females, there were 89.7 males. For every 100 females age 18 and over, there were 84.2 males. The median income for a household in the city was $37,500, and the median income for a family was $50,268. Males had a median income of $32,225 versus $23,500 for females. The per capita income for the city was $18,308.
Bidentate ligands bind to metal ions forming a chelate ring. Ligands of higher denticity form two or more chelate rings. Ethylenediamine, 2,2'-bipyridine, and 1,10-phenanthroline form C2N2M chelate rings. Just like in organic chemistry, 5- and 6-membered chelate rings predominate.
According to Pons, communist states carried out ethnic cleansing, most notably the forced population transfer in the Soviet Union and the Cambodian genocide, as part of an effort to extend state control by homogenising their populations and removing ethnic groups that maintained their "cultural, political and economic distinctiveness". Such states have been accused of genocidal acts in China, Poland, and Ukraine; there is still a debate among scholars whether ideology played a role, to what extent, and whether they meet the legal definition of genocide. For Robert Service, the Soviet Union and China enforced collectivisation, and their widespread use of forced labour in labour camps, such as the Gulag and Laogai, was inherited from Nazi Germany. Although some non-communist states used forced labour, according to Service what was different was "the dispatch of people to the camps for no reason other than the misfortune of belonging to a suspect social class." According to Pons, this was justified by Marxist–Leninist ideology and seen as a means of "redemption". According to Service, their economic policies are blamed for causing major famines such as the Holodomor and Great Chinese Famine; however, scholars disagree on the Holodomor genocide question, and Nobel laureate Amartya Sen put the Great Chinese Famine in a global context, stating that lack of democracy was the major culprit and comparing it to other famines in capitalist countries.
Sources: en.wikipedia.org
=== 1985 === February 6: The Reagan Doctrine commits the United States of America to supporting anti-Communist insurgencies in the Third World. March 10: General Secretary of the Communist Party of the Soviet Union Konstantin Chernenko dies. March 11: Mikhail Gorbachev becomes leader of the Soviet Union. March 15: Military rule ends in Brazil. March 24, 1985: Major Arthur D. Nicholson, a US Army Military Intelligence officer is shot to death by a Soviet sentry in East Germany. He is listed as the last US casualty in the Cold War. April 11: Enver Hoxha dies. Ramiz Alia takes over as First Secretary of the Party of Labor of Albania, becoming the de facto leader of Albania. April 22: The Trial of the Juntas convenes to prosecute the members of the National Reorganization Process (the military junta that governed Argentina from 1976 to 1983) for war crimes and crimes against humanity committed during its existence. May 20: John Anthony Walker is arrested by the FBI. August 6: Coinciding with the 40th anniversary of the atomic bombings of Hiroshima and Nagasaki, the Soviet Union begins what it has announced is a 5-month unilateral moratorium on the testing of nuclear weapons. The Reagan administration dismisses the dramatic move as nothing more than propaganda and refuses to follow suit. Gorbachev declares several extensions, but the United States fails to reciprocate, and the moratorium comes to an end on February 5, 1987. November 7: Crisis of Sigonella, diplomatic conflict between Italy and the United States.
The treatment at that time, endorsed by the leading German ophthalmologist Albrecht von Graefe, was an attempt to physically reshape the cornea by chemical cauterization with a silver nitrate solution and application of a miosis-causing agent with a pressure dressing. In 1888, the treatment of keratoconus became one of the first practical applications of the then newly invented contact lens, when the French physician Eugène Kalt manufactured a glass scleral shell that improved vision by compressing the cornea into a more regular shape. Since the start of the 20th century, research on keratoconus has both improved understanding of the disease and greatly expanded the range of treatment options. The first successful corneal transplantation to treat keratoconus was done in 1936 by Ramón Castroviejo.
=== Investigations === Diabetic ketoacidosis may be diagnosed when the combination of hyperglycemia (high blood sugars), ketones in the blood or on urinalysis and acidosis are demonstrated. In about 10% of cases the blood sugar is not significantly elevated ("euglycemic diabetic ketoacidosis"). A pH measurement is performed to detect acidosis. Blood from a vein is adequate, as there is little difference between the arterial and the venous pH; arterial samples are only required if there are concerns about oxygen levels. Ketones can be measured in the urine (acetoacetate) and blood (β-hydroxybutyrate). When compared with urine acetoacetate testing, capillary blood β-hydroxybutyrate determination can reduce the need for admission, shorten the duration of hospital admission and potentially reduce the costs of hospital care. At very high levels, capillary blood ketone measurement becomes imprecise. In addition to the above, blood samples are usually taken to measure urea and creatinine (measures of kidney function, which may be impaired in DKA as a result of dehydration) and electrolytes. Furthermore, markers of infection (complete blood count, C-reactive protein) and acute pancreatitis (amylase and lipase) may be measured. Given the need to exclude infection, chest radiography and urinalysis are usually performed. If cerebral edema is suspected because of confusion, recurrent vomiting or other symptoms, computed tomography may be performed to assess its severity and to exclude other causes such as stroke.
Sources: en.wikipedia.org
Selank is a seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.
Tuftsin is a natural tetrapeptide derived from the Fc portion of immunoglobulin G. Selank retains that tetrapeptide at its N-terminus and adds three residues to improve resistance to enzymatic breakdown. The relationship is structural, and the two molecules are not interchangeable in experimental work.
It holds a product registration in Russia for intranasal use as an anxiolytic. Registrations of that kind are not automatically accepted by regulators elsewhere. In most other countries it is treated as an unapproved substance or a research material.
Sealed, desiccated storage at -20 °C or colder is the standard recommendation for research-grade material. Vials should reach room temperature before they are opened, which limits condensation. Repeated temperature cycling is discouraged.