Pro-Gly-Pro 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.
Updated 2026-07-25. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
| Property | Value | Notes |
|---|---|---|
| Peptide sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues; tuftsin plus a Pro-Gly-Pro tail |
| Molecular formula | C33H57N11O9 | Commonly reported value for the free peptide |
| Monoisotopic mass | Roughly 751.4 Da | Average molecular mass near 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as a lyophilized solid |
| Solubility class | Freely soluble in water | Also dissolves in saline and other polar solvents |
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.
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.
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.
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.
SVB was a commercial bank founded in 1983 and headquartered in Santa Clara, California. At its collapse, SVB was the 16th largest bank in the U.S. by total assets and was heavily skewed toward serving companies and individuals from the technology industry. Nearly half of U.S. venture capital-backed healthcare and technology companies were financed by SVB. Companies such as Airbnb, Cisco, Fitbit, Pinterest, and Block, Inc. have been clients of the bank. In addition to financing venture-backed companies, SVB was well known as a source of private banking, personal credit lines, and mortgages to tech entrepreneurs, and specialized lending money to higher-risk new companies. Silicon Valley Bank required an exclusive relationship of those borrowing from the bank. Prior to Thursday March 9, 2023, SVB was in "sound financial condition", according to the California Department of Financial Protection and Innovation, though an increased number of short sellers began to target SVB earlier in the year. Employees received their annual bonuses on March 10, 2023, hours before the government took control of the company. As of the last call report of the bank, filed on December 31, 2022, it held $209 billion in total assets, with $175.5 billion in total deposits, of which the bank estimated $151.6 billion (86.4 percent) were uninsured.
== Causes == Pulmonary infection by bacteria, viruses and parasites Drugs: antineoplastic drugs, erlotinib, amiodarone Chemical exposure, most notably to diacetyl Vaping: On October 17, 2019, the American Journal of Clinical Pathology reported that lung biopsies from patients with vaping-associated pulmonary illness show acute lung injury patterns, including organizing pneumonia. Ionizing radiations Inflammatory diseases Systemic lupus Rheumatoid arthritis (RA-associated COP) Scleroderma Bronchial obstruction Proximal bronchial squamous cell carcinoma SARS-CoV-2 Analysis of COVID-19 CT imaging along with postmortem lung biopsies and autopsies suggest that the majority of patients with COVID-19 pulmonary involvement also have secondary organizing pneumonia (OP) or its histological variant, acute fibrinous and organizing pneumonia, which are both well-known complications of viral infections. It was identified in 1985, although its symptoms had been noted before but not recognised as a separate lung disease. The risk of COP is higher for people with inflammatory diseases like lupus, dermatomyositis, rheumatoid arthritis, and scleroderma. It most commonly presents in the 5th or 6th decade of life and it is exceedingly rare in children.
== History == Atractylosides have been used as poisons since at least 100 AD, though it was not isolated and characterized until 1868 by LeFranc, after extracting it from Atractylis gummifera. After high-profile accidental poisonings—children in Italy and Algeria ate parts of the plant in 1955 and 1975, respectively—renewed interest in atractyloside resulted in future research. Historically, the ATR plant sources have been used for numerous reasons: whether for its therapeutic properties, magico-religious purposes, or its toxicity. While its therapeutic uses may be due to the coincidental presence of other compounds, some uses of ATR-containing plants include treating sinusitis, headaches, syphilitic ulcers, and whitening teeth among other applications. Separately, the Atractylis gummifera is a traditional herb used in North Africa while Callilepis laureola is well known to the Zulu people in South Africa for both therapeutical applications and its spiritual context to ward away evil spirits. When in high dosages, ATR's toxicity has been utilized for suicide and murder, though there have been no especially high-profile incidents reported, at least somewhat due to difficulties identifying ATR poisoning. More commonly than suicide or murder, ATR is a result of accidental poisoning: livestock grazing can poison animals, while an unintended overdose or exposure of a plant containing ATR can poison humans. Particularly, the Atractylis gummifera is easily confused with wild artichoke and other vegetables, and its sweet-tasting roots facilitate its consumption.
An essential amino acid, or indispensable amino acid, is an amino acid that cannot be synthesized from scratch by the organism fast enough to supply its demand, and must therefore come from the diet. Of the 21 amino acids common to all life forms, the nine amino acids humans cannot synthesize are valine, isoleucine, leucine, methionine, phenylalanine, tryptophan, threonine, histidine, and lysine. Six other amino acids are considered conditionally essential in the human diet, meaning their synthesis can be limited under special pathophysiological conditions, such as prematurity in the infant or individuals in severe catabolic distress. These six are arginine, cysteine, glycine, glutamine, proline, and tyrosine. Six amino acids are non-essential (dispensable) in humans, meaning they can be synthesized in sufficient quantities in the body. These six are alanine, aspartic acid, asparagine, glutamic acid, serine, and selenocysteine (considered the 21st amino acid). Pyrrolysine (considered the 22nd amino acid), which is proteinogenic only in certain microorganisms, is not used by and therefore non-essential for most organisms, including humans. The limiting amino acid is the essential amino acid which is furthest from meeting nutritional requirements. This concept is important when determining the selection, number, and amount of foods to consume: Even when total protein and all other essential amino acids are satisfied, if the limiting amino acid is not satisfied, then the meal is considered to be nutritionally limited by that amino acid.
would often encounter the Iraqi 3rd Armored Division in their theater of operations. Once the 1st Marine Division reached Kuwait International Airport they found what remained of the Iraqi 12th Armored Brigade, 3rd Armored Division defending it. The Marines destroyed 30 to 40 Iraqi T-72 tanks which had taken up defensive positions around the airport. The Iraqi 3rd Armored Division losses included more than 250 T-55/62s and 70 T-72 tanks by the end of combat operations. The Iraqi 3rd Armored Division would be totally destroyed. The 2nd Marine Division played a major role repelling the attempted Iraqi invasion of Saudi Arabia which is known as the Battle of Khafji. The 2nd Marine Division also faced heavy resistance during the Battle of Kuwait International Airport. The battle featured the "Reveille Engagement" which went on to become the largest tank battle in United States Marine Corps' entire history. Marine Reserve unit Bravo Company, 4th Tank Battalion, 4th Marine division was assigned to the 2nd Marine Division. Bravo Company destroyed a total of 119 enemy vehicles and took over 800 POWs by the end of combat operations. The 1st Tank Battalion claimed 50 Iraqi T-55 and T-62 tanks and 25 APCs. The 3rd Battalion claimed 57 T-55s and T-62s along with 5 T-72s, 7 APCs, and 10 trucks. The 8th Battalion destroyed more than three dozen tanks and a number of other vehicles. U.S. Marine Corps armor units would destroy hundreds of Iraqi tanks by the end of combat operations. U.S.
Sources: en.wikipedia.org
=== Subclinical hypothyroidism === There is no evidence of a benefit from treating subclinical hypothyroidism in those who are not pregnant, and there are potential risks of unnecessary overtreatment. Untreated subclinical hypothyroidism may be associated with a modest increase in the risk of coronary artery disease when the TSH is over 10 mIU/L. There may be an increased risk for cardiovascular death. A 2007 review found no benefit of thyroid hormone replacement except for "some parameters of lipid profiles and left ventricular function". There is no association between subclinical hypothyroidism and an increased risk of bone fractures, nor is there a link with cognitive decline. American guidelines recommend that treatment should be considered in people with symptoms of hypothyroidism, detectable antibodies against thyroid peroxidase, a history of heart disease, or are at an increased risk for heart disease if the TSH is elevated but below 10 mIU/L. American guidelines further recommend universal treatment (independent of risk factors) in those with TSH levels that are markedly elevated; above 10 mIU/L because of an increased risk of heart failure or death due to cardiovascular disease. NICE recommends that those with a TSH above 10 mIU/L should be treated in the same way as overt hypothyroidism. Those with an elevated TSH but below 10 mIU/L who have symptoms suggestive of hypothyroidism should have a trial of treatment but intend to stop this if the symptoms persist despite normalization of the TSH.
=== Brass or square === One brass is exactly 100 square feet (9.29 m2) area (used in measurement of work done or to be done, such as plastering, painting, etc.). The same word is used, however, for 100 cubic feet (2.83 m3) of estimated or supplied loose material, such as sand, gravel, rubble, etc. This unit is prevalent in the construction industry in India. The same area is called a square in the construction industry in North America, and was historically used in Australia by real estate agents. A roof's area may be calculated in square feet, then converted to squares.
PFOA exposure in the Danish general population was not associated with an increased risk of prostate, bladder, pancreatic, or liver cancer. Maternal PFOA levels were not associated with an offspring's increased risk of hospitalization due to infectious diseases, behavioral and motor coordination problems, or delays in reaching developmental milestones.
Amplifications (or gene duplications) or repetition of a chromosomal segment or presence of extra piece of a chromosome broken piece of a chromosome may become attached to a homologous or non-homologous chromosome so that some of the genes are present in more than two doses leading to multiple copies of all chromosomal regions, increasing the dosage of the genes located within them. In some cases, only a fraction of a gene is duplicated, producing a gene shorter that the original. In others, the duplicated gene (or fraction of gene) is copied and inserted right after the original DNA sequence (a tandem duplication) resulting in a longer gene. In the long rung, such multiplicative phenomena dominate the distribution of gene lengths. Polyploidy, duplication of entire sets of chromosomes, potentially resulting in a separate breeding population and speciation. Deletions of large chromosomal regions, leading to loss of the genes within those regions. Mutations whose effect is to juxtapose previously separate pieces of DNA, potentially bringing together separate genes to form functionally distinct fusion genes (e.g., bcr-abl). Large scale changes to the structure of chromosomes called chromosomal rearrangement that can lead to a decrease of fitness but also to speciation in isolated, inbred populations. These include: Chromosomal translocations: interchange of genetic parts from nonhomologous chromosomes. Chromosomal inversions: reversing the orientation of a chromosomal segment. Non-homologous chromosomal crossover.
North America For the United States, the GLC, advertised as the Great Little Car, was only offered with one engine at a time. The new GLC overlapped with the old-style Mizer for part of 1977 and was produced through 1980 before being replaced by the next-generation GLC. The marketing campaign in the U.S. had the words "Great Little Car" set to the tune of Spanish Flea. Thanks to the safety bumpers mandated by federal regulations, the 1979 base GLC three-door weighed in at 1,995 lb (905 kg) and was 154.3 in (3,920 mm) long. The station wagon continued to be offered until the 1986 model year. For the 1979 model year, the original 52 hp (39 kW) 1272 cc four was replaced with a 1415 cc engine producing 65 hp (48 kW). In addition to three- and five-door hatchbacks, as well as the wagon, there was also a GLC Sport version which offered a five-speed rather than the four-speed manual or the three-speed automatic installed in other versions. After the introduction of the front-wheel-drive GLC the carry-over station wagon's engine was replaced with the new E5 model of 1490 cc, although claimed power dropped somewhat, to 63 hp (47 kW).
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.
No peptide with this exact sequence has been identified as an endogenous substance. It is a laboratory-designed analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The Pro-Gly-Pro extension has no known natural source.
Proline introduces conformational constraints that make a peptide less accessible to common peptidases. This is a standard stabilization strategy in peptide design. The added residues also increase the distance between the active tuftsin portion and typical cleavage sites.
It is a seven-amino-acid peptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, produced by chemical synthesis rather than extracted from biological tissue. Its design is based on tuftsin, a natural immunomodulatory tetrapeptide. The C-terminal Pro-Gly-Pro segment is a common stabilising motif in short regulatory peptides.