amino acid sequence is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2025-08-18. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Handling follows standard practice for research peptides. Material is weighed in a low-humidity environment because the powder absorbs atmospheric moisture. Purity is reported as the percentage area of the main peak in a chromatogram, with specifications commonly set at 95 percent or higher; values below that threshold indicate the presence of truncated or modified species. Residual trifluoroacetate from purification is often present and may affect mass balance. Certificates of analysis should state the analytical method, the column and gradient used, and the lot-specific retention time so that results can be compared across suppliers.
Identity and purity of selank are established with reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The peptide elutes from C18 columns with acetonitrile gradients in water containing trifluoroacetic acid or formic acid, and detection is usually performed by ultraviolet absorbance near 214 nm. Electrospray ionization in positive mode gives a doubly protonated ion near m/z 377, consistent with a mass of about 752 Da. Amino acid analysis or tandem mass spectrometry of fragment ions confirms the sequence. Because the molecule has no aromatic residues, it lacks a usable 280 nm chromophore, so low-wavelength detection or mass spectrometry is required.
| 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 |
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, with mass spectrometry used to confirm molecular mass and sequence information. Amino acid analysis and peptide mapping may supplement these methods. Certified reference standards are scarce, and many commercial lots are sold as research chemicals without a pharmacopoeial monograph. Regulatory treatment differs by country: Selank is a registered prescription medicine in Russia, while in the European Union and the United States it is not an approved drug and may fall under research-chemical or unapproved-product frameworks.
Selank is a hydrophilic peptide and dissolves readily in water and in aqueous buffers. The lyophilised powder is typically a white to off-white solid. Because short peptides are prone to hydrolysis and oxidation, handling benefits from limiting exposure to heat, moisture and strong light. Working solutions are commonly prepared in sterile water or saline, and repeated freeze-thaw cycles are avoided to reduce aggregation and loss of activity. These practices reflect general laboratory convention rather than published stability specifications.
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
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 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.
Most such markets do not trade in wild or exotic animals, but some that do have been linked to outbreaks of zoonotic diseases including COVID-19, H5N1 avian flu, severe acute respiratory syndrome (SARS), and mpox. Several countries have banned markets from holding wildlife. Media reports that fail to distinguish between food markets generally and those with live animals or wildlife, as well as insinuations of fostering wildlife smuggling, have been blamed for fueling Sinophobia related to the COVID-19 pandemic.
=== Elevation and pinecone production === Some growers claim that the elevation of the pinyon pine is an important determinant of the quantity of pine cone production and, therefore, will largely determine the number of pine nuts the tree will yield. The US Department of Agriculture notes that variation in cone production between trees growing on identical sites is often observed. American pinyon pine cone production is most commonly found at an elevation between 1,800 and 2,600 m (6,000 and 8,500 ft), and ideally at 2,100 m (7,000 ft). This is due to higher temperatures at elevations lower than 1,800 m (6,000 ft) during the spring, which dry up humidity and moisture content (particularly snow packs) that provide for the tree throughout the spring and summer, causing little nourishment for pine cone maturity. Although several other environmental factors determine the conditions of the ecosystem (such as clouds and rain), the trees tend to abort cones without sufficient water. High humidity encourages cone development. There are certain topographical areas found in lower elevations, such as shaded canyons, where the humidity remains constant throughout the spring and summer, allowing pine cones to fully mature and produce seed. At elevations above 2,600 m (8,500 ft), the temperature substantially drops, drastically affecting the state of the dormant cone. During the winter, frequent dramatic changes in temperature, drying, and gusty winds make the cones susceptible to freeze-drying that permanently damages them; in this case, growth is stunted, and the seeds deteriorate.
=== Adipose tissue === Insulin resistance in fat cells results in reduced uptake of circulating lipids and increased hydrolysis of stored triglycerides. This leads to elevated free fatty acids in the blood plasma and can further worsen insulin resistance. Since insulin is the primary hormonal signal for energy storage into fat cells, which tend to retain their sensitivity in the face of hepatic and skeletal muscle resistance, insulin resistance stimulates the formation of new fatty tissue and accelerates weight gain. Insulin resistance is strongly associated with intestinal-derived apoB-48 production rate in insulin-resistant subjects and people with type 2 diabetes. Insulin resistance often is found in people with visceral adiposity, hypertension, hyperglycemia, and dyslipidemia involving elevated triglycerides, small dense low-density lipoprotein (sdLDL) particles, and decreased high-density lipoprotein (HDL) cholesterol levels. With respect to visceral adiposity, a great deal of evidence suggests two strong links with insulin resistance. First, unlike subcutaneous adipose tissue, visceral adipose cells produce significant amounts of proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-a), and interleukins-1 and -6. In numerous experimental models, these proinflammatory cytokines disrupt normal insulin action in fat and muscle cells and may be a major factor in causing the whole-body insulin resistance observed in patients with visceral adiposity.
Bristol was made a city in 1542, with the former Abbey of St Augustine becoming Bristol Cathedral, following the Dissolution of the Monasteries by Henry VIII. The Dissolution also saw the surrender to the king of all of Bristol's friaries and monastic hospitals, together with St James' Priory, St Mary Magdalen nunnery and the college at Westbury on Trym. In the case of the friaries at Greyfriars and Whitefriars, the priors had fled before the arrival of the royal commissioners, and at Whitefriars a succession of departing priors had plundered the friary of its valuables. Although the commissioners had not been able to point to as much religious malpractice in Bristol as elsewhere, there is no record of Bristolians raising any objections to the royal seizures. In 1541 Bristol's civic leaders took the opportunity of buying up lands and properties formerly belonging to St Mark's Hospital, St Mary Magdalen, Greyfriars and Whitefriars for a total of a thousand pounds. Bristol thereby became the only municipality in the country which has its own chapel, at St Mark's. Bristol Grammar School was established in 1532 by the Thorne family and in 1596 John Carr established Queen Elizabeth's Hospital, a bluecoat school charged with 'the education of poor children and orphans'. Trade continued to grow: by the mid-16th century imports from Europe included, wine, olive oil, iron, figs and other dried fruits and dyes; exports included cloth (both cotton and wool), lead and hides.
=== Foot Care === Foot monitoring can help in predicting the likelihood of developing diabetic foot ulcers, a common complication in persistent uncontrolled diabetes. A common method for this is using a special thermometer to look for spots on the foot that have higher temperature which indicate the possibility of an ulcer developing. At the same time there is no strong scientific evidence supporting the effectiveness of at-home foot temperature monitoring. The current guideline in the United Kingdom recommends collecting 8-10 pieces of information for predicting the development of foot ulcers. A simpler method proposed by researchers provides a more detailed risk score based on three pieces of information (insensitivity, foot pulse, previous history of ulcers or amputation). This method is not meant to replace individuals regularly checking their own feet but complement it.
Sources: en.wikipedia.org
== Expression == In placental mammals, including humans, the highest levels of DAO expression are observed in the digestive tract (intestinal mucosa) and the placenta. DAO expression is also observed in kidney of various species. DAO is also expressed in eosinophils.
=== Research environment === In the United States, research in digital agriculture is primarily funded by the National Institute of Food and Agriculture (NIFA) which comes under the US Department of Agriculture and to a lesser extent, by the National Science Foundation. Two large institutes applying IoT or artificial intelligence in digital agriculture have been unveiled by these funding organizations working together.
college sports) SOD (i/a) School Of Dentistry Statement Of Difference(s) Statement Of Direction Statement Of Documentation Statement Of Duty/Duties SOE (i) Secret Of Evermore Special Operations Executive (WWII British organization) State Of Emissions (EW) SOF (a/i) Special Operations Force(s) Status of Forces SOFIA – (a) Stratospheric Observatory For Infrared Astronomy SOGAT (a) Society of Graphical and Allied Trades Former British printing union SOHC – (i) Single-OverHead-Cam engine SOHO – (p) Solar and Heliospheric Observatory SOI (i) Signal Operating Instruction (i) Southern Oscillation Index SOL – (i) Shit Out of Luck SOLIS – (i) Synoptic Optical Long-term Investigations of the Sun som – (s) Somali language (ISO 639-2 code) SOM (a) Simulation Object Model (s) Somalia (ISO 3166 trigram) Sonar – (p) SOund Navigation And Ranging SOP (i) Standing/Standard Operating Procedure State of Play SOR (i) State Of Readiness Statement Of Requirements SOS (s) Somali shilling (ISO 4217 currency code) Save Our Souls SOSTAR – (a) Stand-Off Surveillance and Target Acquisition Radar sot – (s) Sotho language (ISO 639-2 code) SOUTHAG – (p) Southern Army Group SOUTHCOM – (p) (U.S.) Southern Command SOV – (i) Single Occupant Vehicle SOW – (i) Statement Of Work SOWHAT – (p) RESNA Subcommittee on Wheelchairs and Transportation SOX – (p) Sarbanes–Oxley Act
Robertson published his findings in the British Medical Journal in 1916 and, with the help of a few like-minded individuals (including the eminent physician Edward William Archibald), was able to persuade the British authorities of the merits of blood transfusion. Robertson went on to establish the first blood-transfusion apparatus at a Casualty Clearing Station on the Western Front in the spring of 1917. Robertson did not test crossmatching so that one died of hemolysis in his 1916 transfusion, and three in 1917. Oswald Hope Robertson, a medical researcher and U.S. Army officer, was attached to the RAMC in 1917, where he became instrumental in establishing the first blood banks in preparation for the anticipated Third Battle of Ypres. He used sodium citrate as the anticoagulant; blood was extracted from punctures in the vein and was stored in bottles at British and American Casualty Clearing Stations along the Front. Robertson also experimented with preserving separated red blood cells in iced bottles. Geoffrey Keynes, a British surgeon, developed a portable machine that could store blood to enable transfusions to be carried out more easily.
chromosome condensation The process by which eukaryotic chromosomes become shorter, thicker, denser, and more conspicuous under a microscope during prophase due to systemic coiling and supercoiling of chromatic strands of DNA in preparation for cell division.
Sources: en.wikipedia.org
(There can also be silent mutations in nucleotides outside of the coding regions, such as the introns, because the exact nucleotide sequence is not as crucial as it is in the coding regions, but these are not considered synonymous substitutions.) A nonsynonymous substitution replaces a codon with another codon that codes for a different amino acid, so that the produced amino acid sequence is modified. Nonsynonymous substitutions can be classified as nonsense or missense mutations: A missense mutation changes a nucleotide to cause substitution of a different amino acid. This in turn can render the resulting protein nonfunctional. Such mutations are responsible for diseases such as Epidermolysis bullosa, sickle-cell disease, and SOD1-mediated ALS. On the other hand, if a missense mutation occurs in an amino acid codon that results in the use of a different, but chemically similar, amino acid, then sometimes little or no change is rendered in the protein. For example, a change from AAA to AGA will encode arginine, a chemically similar molecule to the intended lysine. In this latter case the mutation will have little or no effect on phenotype and therefore be neutral. A nonsense mutation is a point mutation in a sequence of DNA that results in a premature stop codon, or a nonsense codon in the transcribed mRNA, and possibly a truncated, and often nonfunctional protein product. This sort of mutation has been linked to different diseases, such as congenital adrenal hyperplasia. (See Stop codon.)
=== Second term as Environment Secretary: 1990–1992 === Heseltine disappointed many of his supporters by not pushing for them to get jobs in Major's new administration. Ian Grist was sacked from the Welsh Office and Michael Mates was eventually given a minister of state position following the 1992 election. There were suggestions that Heseltine might be appointed Home Secretary, but Heseltine advertised his lack of interest in the position, and Major insisted that he had not offered it to him. By contrast, his enthusiasm for industrial policy made it impossible for him to be appointed secretary of state for trade and industry, the job he most coveted. After a handshake of reconciliation on the steps of 10 Downing Street, Major appointed Heseltine to the Environment, the same job he had held a decade earlier. Civil servants found him a secure and mature character in the second interaction, and keener to conciliate local councils, but at the same time a grander and more detached individual, aware that he had already earned a place in history and had the energy of a political heavyweight. In a May 1990 article Heseltine had proposed that the Poll Tax be reformed rather than abolished. He now had a remit to reform it, and invited the opposition parties to take part in his review of options (Labour did not; the Liberal Democrats did, and proposed a local income tax). Heseltine insisted that Michael Portillo, who had been a major cheerleader for the tax, be retained as Minister of State for Local Government.
== Research and career == In 1975, Theo Wallimann completed his Ph.D. Dissertation on “M-line-bound Creatine Kinase and Myofibrillar Structure” in the laboratory of Prof. Hans M. Eppenberger at the Institute of Cell Biology at ETH Zurich with distinction and received the ETH prize and medal. From 1975 - 1981, Wallimann worked as a post-doctoral research associate with Andrew G. Szent-Györgyi , at the Biology Department of Brandeis University on the subject of "Myosin-linked calcium regulation of muscle contraction". After rejoining the Biology Dept of the ETH-Zurich in 1981, Wallimann became a Lecturer in 1984 with his Habilitation on: "Localization and function of M-line-bound creatine kinase: M-band model and Phospho-Creatine Shuttle"). In 1994, Wallimann was awarded the title of Professor and in the next two years he became Head and Deputy Head of the Institute of Cell Biology. Wallimann resigned from his post in June 2008 and is now Emeritus and member of the ETH Alumni organisation. In 2005, Wallimann was awarded with the Alfred-Vogt-Prize in 2005 and in 2023, 2024 and 2025 he received the Research.com Recognition Leader Award for Biology and Biochemistry in Switzerland. In 2025, Theo Wallimann has been honored by the International Society of Sports Nutrition with a “Life-time Achievement Award” for his research on the «Creatine Kinase System and Creatine», at the Internatl. Congress on «Creatine for Health», held during March 12th-16th 2025 in Munich, Germany: https://creatineforhealth.com/creatine-conference-2025/
== Retirement (1970–1979) == Even though Ron "retired" from live performances, he continued to hone his guitar skills, acquiring influences from then current Hard rock, Southern rock and Heavy metal acts like Deep Purple (guitarist Ritchie Blackmore being a seminal influence), Judas Priest, Styx, Blue Öyster Cult, Lynyrd Skynyrd and Rush. Ron began recording his own demos at home and studied the keyboard as well.
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.
Identity is confirmed by matching the retention time in reversed-phase chromatography against a reference standard and by measuring the molecular mass with mass spectrometry. Tandem mass spectrometry or amino acid analysis can verify the sequence of the seven residues. Because the peptide contains no aromatic amino acids, detection at 280 nm is not useful.