proteolysis comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-03-15. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Modeled on tuftsin |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues |
| Approximate molecular mass | Around 750 Da | Depends on counter-ion and hydration |
| Common forms | Lyophilized powder | Also described as aqueous solution |
| Primary origin of research | Russian laboratories | Mid-1990s onward |
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.
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.
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.
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
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.
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
=== Alcoholism === There have been studies showing that variations in ADH that influence ethanol metabolism have an impact on the risk of alcohol dependence. The strongest effect is due to variations in ADH1B that increase the rate at which alcohol is converted to acetaldehyde. One such variant is most common in individuals from East Asia and the Middle East, another is most common in individuals from Africa. Both variants reduce the risk for alcoholism, but individuals can become alcoholic despite that. Researchers have tentatively detected a few other genes to be associated with alcoholism, and know that there must be many more remaining to be found. Research continues in order to identify the genes and their influence on alcoholism.
After Ceaușescu was summarily executed, the National Salvation Front (FSN) quickly took power, promising free and fair elections within five months. Elected in a landslide the following May, the FSN reconstituted as a political party, installed a series of economic and democratic reforms, with further social policy changes being implemented by later governments. From that point on, Romania has become far more integrated with the West. Romania became a member of NATO and the European Union in 2004 and 2007, respectively.
In April 2018, Boston Market announced that it was expanding its menu to offer rotisserie prime rib nationwide, three days a week. In 2019, the chain closed 45 locations, with one report noting competition with rotisserie chickens sold at regular supermarket chains. In 2020, it introduced baby back ribs paired with Sweet Baby Ray's sauce. In April 2020, Sun Capital Partners sold Boston Market to Engage Brands, LLC, a company of Rohan Group, owned by Jignesh "Jay" Pandya. This started a difficult period in which the company stopped paying its suppliers, rent, and some employees. This resulted in over 150 lawsuits. In 2023, New Jersey shut down 27 locations when it was determined employees were owed hundreds of thousands of dollars. The chain started with about 300 locations at the start of 2023, but was down to 79 locations later that year, and by early 2024 there were fewer than 30 locations even though the chain opened a new location in India.
== Discovery == The original discovery of Substance P (SP) was in 1931 by Ulf von Euler and John H. Gaddum as a tissue extract that caused intestinal contraction in vitro. Its tissue distribution and biologic actions were further investigated over the following decades. The eleven-amino-acid structure of the peptide was determined by Chang, et al. in 1971. In 1983, Neurokinin A (previously known as substance K or neuromedin L) was isolated from porcine spinal cord and was also found to stimulate intestinal contraction.
Sources: en.wikipedia.org
Pedro Cuatrecasas (27 September 1936 – 19 March 2025) was a Spanish-born American biochemist and academic who was an adjunct professor of Pharmacology & Medicine at the University of California San Diego.
== Treatment == Supportive care in those with PAH involves using diuretics as needed for fluid overload, supplemental oxygen for hypoxemia, following a low sodium diet, an exercise program (such as walking), and routine immunizations. Vasoconstricting medications (frequently found in cough, cold and sinus formulations) should be avoided. Cardiopulmonary rehabilitation programs may be used for symptom control, patient education and counselling. Anticoagulation, once universally used for PAH, is now indicated in idiopathic PAH, and its use is evaluated based on patient factors. Disease specific therapy for PAH has improved disease free survival, symptom scores and mortality. Treatments consist of targeting the various aberrant pathways involved in the disease. For those with moderate to severe disease, dual therapy targeting at least 2 different disease specific pathways is indicated. Dual therapy is associated with greater mortality and disease free survival benefits over monotherapy. PDE5 inhibitors (including sildenafil and tadalafil are used to dilate blood vessels by inhibiting the degradation of Cyclic guanosine monophosphate (cGMP). cGMP inhibits pulmonary artery smooth muscle proliferation and causes pulmonary artery smooth muscle cell relaxation, thus acting as a vasodilator. Riociguat also causes vasodilation by stimulating cGMP production. Endothelin receptor antagonists cause vasodilation as well by blocking the action of the potent vasoconstrictor and vascular smooth muscle cell proliferation activator endothelin-1.
=== Infants === Infantile beriberi usually occurs between two and six months of age in children whose mothers have inadequate thiamine intake. It may present as either wet or dry beriberi. In the acute form, the baby develops dyspnea and cyanosis and soon dies of heart failure. These symptoms may be described in infantile beriberi:
Burkett (1984), award-winning correspondent for WABC-TV Matthew Cooper (1984), Time magazine White House correspondent and defendant in the Valerie Plame investigation Tom Watson (1984), journalist, entrepreneur Thomas Vinciguerra (1985), journalist, editor and author Naftali Bendavid (1986), Congress correspondent for The Wall Street Journal Susan Benesch (1986), journalist, free speech advocate Elizabeth Rubin (1987), journalist for The New York Times Magazine, sister of Bloomberg News executive editor James Rubin '82 Aram Roston (1988), investigative journalist Edward Lewine (1989), author and freelance journalist Sam Marchiano (1989), television sportscaster, documentarian and activist, daughter of sportscaster Sal Marchiano David Streitfeld (1989), book reporter for The Washington Post; winner of the 2013 Pulitzer Prize for Explanatory Reporting Caroline Glick (1991), Israeli journalist, editor, writer Warren St. John (1991), journalist for The New York Times and former CEO of Patch Michael J. Socolow (1991), broadcast journalist and professor at the University of Maine Jesse Eisinger (1992), Pulitzer Prize-winning reporter for ProPublica Jean H.
The tissues of many animals respond to injury with inflammation, resulting in repair of the wound. Inflammation occurs in many taxa, but the nature of the response varies widely. In Hydra, a cnidarian, damage to the area around the mouth is fully healed within 20 minutes. Animals in several phyla, including annelids, arthropods, cnidaria, molluscs, nematodes, and vertebrates are able to produce antimicrobial peptides to fight off infection following an injury.
Sources: en.wikipedia.org
Grinners Food Systems Limited, the franchiser of Greco Pizza (since 1981) and Captain Sub, is a Truro, Nova Scotia-based company. It is owned by Trucorp Investments Incorporated. Trucorp, headquartered in Dieppe, New Brunswick, also owns Bonte Foods Limited, Frank and Gino's Restaurants, and Chris Brothers food products. Established in Moncton, New Brunswick in 1977, Greco Pizza is one of Atlantic Canada's largest pizza chains. Menu items include pizza, donair, salads, garlic fingers, and the restaurant's proprietary dipping sauces. Many of the over 170 locations in Quebec, Ontario, New Brunswick, Nova Scotia, and Newfoundland operate co-branded with Captain Submarine. Both are quick-service restaurants. Captain Submarine was acquired by Grinner's in 2002, when it only had nine locations (21 fewer than it had in the 1980s). Many of the stores franchised since then also sell Greco Pizza items. The purchase brought the number of Grinners franchised restaurants from 111 to 120.
=== Natural resources and energy === Belize is known to have a number of economically important minerals, but none in quantities large enough to warrant mining. These minerals include dolomite, barite (source of barium), bauxite (source of aluminium), cassiterite (source of tin), and gold. In 1990 limestone, used in road construction, was the only mineral resource exploited for domestic or export use. In 2006, the cultivation of newly discovered crude oil in the town of Spanish Lookout has presented new prospects and problems for this developing nation. Access to biocapacity in Belize is much higher than world average. In 2016, Belize had 3.8 global hectares of biocapacity per person within its territory, much more than the world average of 1.6 global hectares per person. In 2016 Belize used 5.4 global hectares of biocapacity per person – their ecological footprint of consumption. This means they use more biocapacity than Belize contains. As a result, Belize is running a biocapacity deficit.
which is conservative, non-traumatic and less invasive and can be performed on an outpatient basis under local anaesthetic in a doctor's office and has the advantage of healing very quickly with little or no significant cosmetic alteration to the appearance of the penis.
large excesses of solution-phase reagents can be used to drive reactions quickly to completion impurities and excess reagents are washed away and minimal purification is required following production the process is amenable to automation on computer-controlled solid-phase synthesizers simple, automated chemical processes make production scalable with high batch-to-batch consistency no competition for cell-based manufacturing space for cost efficient manufacturing capacity
Sources: en.wikipedia.org
Selank is a synthetic peptide made of seven amino acids. It is modeled on tuftsin, a natural tetrapeptide, with an added three-residue tail. It is not a small-molecule drug.
It originates from research in Russia, associated with the Institute of Molecular Genetics of the Russian Academy of Sciences. The first descriptions date to the mid-1990s. Most published studies come from Russian laboratories.
No, Selank itself does not occur naturally. Its backbone is based on tuftsin, which is produced in the body, but the seven-residue version is a synthetic construct. It is supplied as a manufactured peptide.
Dry powder is best kept sealed, protected from light, and held at minus 20 degrees Celsius or below. Desiccant packaging helps limit moisture uptake because the material is hygroscopic. A sealed vial should be allowed to equilibrate to room temperature before opening to reduce condensation.