The short version of Pro-Gly-Pro fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-11-13 and is reviewed periodically as new material appears.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
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 |
|---|---|---|
| Common route | Intranasal | Also injected in some animal work |
| Solubility class | Freely soluble in water | Solid form is hygroscopic |
| Typical storage | About -20 degrees Celsius | Keep desiccated and dark |
| Purity method | Reverse-phase HPLC | Reported as area percent |
| Confirmatory method | Mass spectrometry | Verifies expected molecular mass |
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.
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.
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.
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.
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.
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.
== External links == CUTL1+protein,+human at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Human CUX1 genome location and CUX1 gene details page in the UCSC Genome Browser. This article incorporates text from the United States National Library of Medicine, which is in the public domain.
Dorothy Mary Crowfoot Hodgkin (née Crowfoot; 12 May 1910 – 29 July 1994) was an English chemist who advanced the technique of X-ray crystallography to determine the structure of biomolecules, which became essential for structural biology. She received the 1964 Nobel Prize in Chemistry, and is the only British woman scientist to have been awarded a Nobel Prize. Among her most influential discoveries are the confirmation of the structure of penicillin as previously surmised by Edward Abraham and Ernst Boris Chain; and mapping the structure of vitamin B12, for which in 1964 she became the third woman to win the Nobel Prize in Chemistry. Hodgkin also elucidated the structure of insulin in 1969 after 35 years of work. Hodgkin used the name "Dorothy Crowfoot" until twelve years after marrying Thomas Lionel Hodgkin, when she began using "Dorothy Crowfoot Hodgkin". Hodgkin is referred to as "Dorothy Hodgkin" by the Royal Society (when referring to its sponsorship of the Dorothy Hodgkin fellowship), and by Somerville College. The National Archives of the United Kingdom refer to her as "Dorothy Mary Crowfoot Hodgkin". The case of her Nobel prize is inscribed 'Crowfoot Hodgkin'.
Ancrod (also known as Viprinex), a serine protease derived from the venom of the Malayan pit vipers, was under development for the treatment of acute ischemic stroke; after Knoll was acquired by Abbott, Abbott licensed the rights to ancrod to Empire Pharmaceuticals, a startup that included a Knoll employee who had worked on ancrod. In 2004 Empire was acquired by Neurobiological Technologies (NTI). Ancrod failed in a Phase III clinical trial in 2008, which led to the demise of NTI.
In the developing embryo, at the hind end lies an inpouching called the cloaca. This, over the fourth to the seventh week, divides into a urogenital sinus and the beginnings of the anal canal, with a wall forming between these two inpouchings called the urorectal septum. The urogenital sinus divides into three parts, with the middle part forming the urethra; the upper part is largest and becomes the urinary bladder, and the lower part then changes depending on the biological sex of the embryo. The prostatic part of the urethra develops from the middle, pelvic, part of the urogenital sinus, which is of endodermal origin. Around the end of the third month of embryonic life, outgrowths arise from the prostatic part of the urethra and grow into the surrounding mesenchyme. The cells lining this part of the urethra differentiate into the glandular epithelium of the prostate. The associated mesenchyme differentiates into the dense connective tissue and the smooth muscle of the prostate. Condensation of mesenchyme, urethra, and Wolffian ducts gives rise to the adult prostate gland, a composite organ made up of several tightly fused glandular and non-glandular components. To function properly, the prostate needs male hormones (androgens), which are responsible for male sex characteristics. The main male hormone is testosterone, which is produced mainly by the testicles. It is dihydrotestosterone (DHT), a metabolite of testosterone, that predominantly regulates the prostate. The prostate gland enlarges over time, until the fourth decade of life.
The most widely used system of crop rotation with rice and vegetables. This system is applicable if the propagule (small piece of rhizome) can be planted early in the year. The rhizomes are harvested in July, after which rice can be planted in the same field. Rice is then harvested in October. From November until March, the field stays either free or contains non-aquatic vegetables, such as cabbage or spinach. Alternatively, the vegetable can also be planted after the harvest of the lotus. Another alternative way is not to harvest the lotus rhizome, even though it is already ripe. A non-aquatic vegetable is planted between the rhizomes into the drained field. The rhizomes are then harvested next March. A third way is to plant lotus in ponds or fields and raise aquatic animals such as fish, shrimp, or crab in the same field. A more efficient use of the water for both, the aquatic animals and lotus production has been identified with this planting pattern.
Sources: en.wikipedia.org
Another widespread trait among modern birds (but see below in regards to fossil groups and extant megapodes) is parental care for young after hatching. Bob Makela and Jack Horner's 1978 discovery of a Maiasaura ("good mother lizard") nesting ground in Montana demonstrated that parental care continued long after birth among ornithopods. A specimen of the oviraptorid Citipati osmolskae was discovered in a chicken-like brooding position in 1993, which may indicate that they had begun using an insulating layer of feathers to keep the eggs warm. An embryo of the basal sauropodomorph Massospondylus was found without teeth, indicating that some parental care was required to feed the young dinosaurs. Trackways have also confirmed parental behavior among ornithopods from the Isle of Skye in northwestern Scotland. However, there is ample evidence of precociality or superprecociality among many dinosaur species, particularly theropods. For instance, non-ornithuromorph birds have been abundantly demonstrated to have had slow growth rates, megapode-like egg burying behavior and the ability to fly soon after birth. Both Tyrannosaurus and Troodon had juveniles with clear superprecociality and likely occupying different ecological niches than the adults. Superprecociality has been inferred for sauropods. Genital structures are unlikely to fossilize as they lack scales that may allow preservation via pigmentation or residual calcium phosphate salts.
In selected reaction monitoring, the first analyzer allows only a single mass through and the second analyzer monitors for multiple user-defined fragment ions over longer dwell-times than could be achieved in a full scan. This increases sensitivity. In product ion scans, the first mass analyzer is fixed to select a particular precursor ion ("parent"), while the second is scanned to find all the fragments ("products", or "daughter ions") to which it can be fragmented in the collision cell. In precursor ion scans, the second mass analyzer is fixed to select a particular fragment ion ("daughter"), while the first is scanned to find all possible precursor ions that could give rise to this fragment. In neutral loss scans, the two mass analyzers are scanned in parallel, but separated by the mass of a molecular subunit of interest to the analyst. Ions are detected if they lose that fixed mass during fragmentation. This can be used to look for any chemical that is capable of losing a particular neutral group, for example a sugar residue. Together, neutral loss and precursor ion scans can be used to hunt for chemicals with particular motifs. Another type of tandem mass spectrometry used for radiocarbon dating is accelerator mass spectrometry, which uses very high voltages, usually in the mega-volt range, to accelerate negative ions into a type of tandem mass spectrometer. The METLIN Metabolite and Chemical Entity Database is the largest repository of experimental tandem mass spectrometry data acquired from standards.
The first variety, a cracker similar to a cross between an unsalted saltine and hardtack, Crown Pilot Crackers. It was a popular item in much of New England and was manufactured by Nabisco until it was discontinued in the first quarter of 2008. It was discontinued once before, in 1996, but a small uprising by its supporters brought it back in 1997. This variety comes in two sub-varieties, Flaky and Barge biscuits. The second is Hard Bread, a traditional hardtack, and is the principal ingredient in fish and brewis, a traditional Newfoundland and Labrador meal. The third variety is Sweet Bread, which is slightly softer than regular hardtack due to a higher sugar and shortening content, and is eaten as a snack food.
Fasting glucose concentration Fasting or random C-peptide concentration Although single-point measurements have the benefit of being convenient and inexpensive, they are generally not regareded as sufficiently informative for early diagnosis of impaired glucose homeostasis or early-stage type 1 diabetes.
== Diagnosis == The diagnosis of copper deficiency may be supported by a person's report of compatible signs and symptoms, findings from a thorough physical examination, and supportive laboratory evidence. Low levels of copper and ceruloplasmin in the serum are consistent with the diagnosis as is a low 24-hour urine copper level. Additional supportive bloodwork findings also include neutropenia and anemia. MRI imaging may demonstrate increased T2 signal of the dorsal column–medial lemniscus pathways.
Sources: en.wikipedia.org
The signature colors for In-N-Out are white, red, and yellow. The white is used for the buildings' exterior walls and the employees' basic uniform. Red is used for the buildings' roofs and the employees' aprons and hats. Yellow is used for the decorative band on the roof and iconic arrow in the logo. However, variations in the color scheme do occur.
The right to take collective action, including the "right to strike" within "the laws of the particular country" is a universal right in international law. However, Australian law is one of the most restrictive on unions' freedom to take action to protect members' interests, and progressive restrictions on voice at work have matched a stagnation of wages. Before 1993, the law formally did not allow strike action at all, although in practice many strikes took place. Disputes were meant to be solved by compulsory arbitration, leading to notable instances of union officers being sued in tort for millions in damages where they took action. This is because under old common law, a strike that breaks a contract may lead to the imposition of industrial torts. Under the Fair Work Act 2009 section 19, industrial action is performing work "in a manner different from that in which it is customarily performed" or "a restriction or limitation on, or a delay in, the performance of work". It is not clear whether picketing is always industrial action, given a Federal Court case before the FWA 2009 doubting that it was, leading to the result that picketing would not be protected action, but also that the FWC could not issue stop orders against pickets.
DBH is inhibited by disulfiram, tropolone, and, most selectively, by nepicastat. It is also inhibited by etamicastat and zamicastat. DBH is reversibly inhibited by l-2H-Phthalazine hydrazone (hydralazine; HYD), 2-1H-pyridinone hydrazone (2-hydrazinopyridine; HP), 2-quinoline-carboxylic acid (QCA), l-isoquinolinecarboxylic acid (IQCA), 2,2'-bi-lH-imidazole (2,2'-biimidazole; BI), and IH-imidazole-4-acetic acid (imidazole-4-acetic acid;[2] IAA). HYD, QCA, and IAA are allosteric competitive.
cytology The study of the morphology, processes, and life history of living cells, particularly by means of light and electron microscopy. The term is also sometimes used as a synonym for the broader field of cell biology.
Morphine is the most abundant opiate found in opium, the dried latex extracted by shallowly scoring the unripe seedpods of the Papaver somniferum poppy. Morphine is generally 8–14% of the dry weight of opium. Przemko and Norman cultivars of the opium poppy, are used to produce two other alkaloids, thebaine and oripavine, which are used in the manufacture of semi-synthetic and synthetic opioids like oxycodone and etorphine. P. bracteatum does not contain morphine or codeine, or other narcotic phenanthrene-type, alkaloids. This species is rather a source of thebaine. Occurrence of morphine in other Papaverales and Papaveraceae, as well as in some species of hops and mulberry trees has not been confirmed. Morphine is produced most predominantly early in the life cycle of the plant. Past the optimum point for extraction various processes in the plant produce codeine, thebaine, and in some cases negligible amounts of hydromorphone, dihydromorphine, dihydrocodeine, tetrahydro-thebaine, and hydrocodone (these compounds are rather synthesized from thebaine and oripavine). In the brains of mammals, morphine is detectable in trace steady-state concentrations. The human body also produces endorphins, which are chemically related endogenous opioid peptides that function as neuropeptides and have similar effects to morphine.
Sources: en.wikipedia.org
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.
Reported human trials are few, brief and originate mainly from one country. They describe effects on anxiety-related measures, but sample sizes are small and reporting is limited. The results are widely regarded as preliminary rather than confirmed.
Reverse-phase liquid chromatography is used to assess purity and separation of related impurities. Mass spectrometry confirms that the observed molecular mass matches the expected peptide. A certificate of analysis from the supplier is the usual document of record.
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.