A practical reference on TKPRPGP: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-08-09 and is reviewed periodically as new material appears.
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.
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
Lyophilized Selank, the dry powder form, is generally stored frozen at minus 20 degrees Celsius or colder for long-term keeping. The solid is hygroscopic and should stay sealed, dry, and protected from light. Once dissolved, the peptide is less stable and is usually held refrigerated at 2 to 8 degrees Celsius for short periods. Repeated freezing and thawing is avoided because it can promote aggregation and loss of activity. Buffers and pH choice also affect how long a solution remains usable.
| 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 |
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
== Pharmacokinetics == Absorption Sulfamethoxazole is well-absorbed when administered topically. It is rapidly absorbed when it is orally administered. Distribution Sulfamethoxazole distributes into most body tissues as well as into sputum, vaginal fluid, and middle ear fluid. It also crosses the placenta. About 70% of the drug is bound to plasma proteins. Its Tmax (or time to reach maximum drug concentration in plasma) occurs 1 to 4 hours after oral administration. The mean serum half-life of sulfamethoxazole is 10 hours. However, the half-life of the drug noticeably increases in people with creatinine clearance rates equal to or less than 30 mL/minute. A half-life of 22–50 hours has been reported for people with creatinine clearances of less than 10 mL/minute. Metabolism Sulfamethoxazole is metabolized in the human liver to at least 5 metabolites. These metabolites are the N4-acetyl-, N4-hydroxy-, 5-methylhydroxy-, N4-acetyl-5-methylhydroxy-sulfamethoxazole metabolites, and an N-glucuronide conjugate. The CYP2C9 enzyme is responsible for the formation of the N4-hydroxy metabolite. In vitro studies suggest sulfamethoxazole is not a substrate of the P-glycoprotein transporter. Excretion Sulfamethoxazole is primarily renally excreted via glomerular filtration and tubular secretion. About 20% of the sulfamethoxazole in urine is the unchanged drug, about 15–20% is the N-glucuronide conjugate, and about 50–70 % is the acetylated metabolite. Sulfamethoxazole is also excreted in human milk.
=== Baculovirus === Baculovirus, a rod-shaped virus which infects insect cells, is used as the expression vector in this system. Insect cell lines derived from Lepidopterans (moths and butterflies), such as Spodoptera frugiperda, are used as host. A cell line derived from the cabbage looper is of particular interest, as it has been developed to grow fast and without the expensive serum normally needed to boost cell growth. The shuttle vector is called bacmid, and gene expression is under the control of a strong promoter pPolh. Baculovirus has also been used with mammalian cell lines in the BacMam system. Baculovirus is normally used for production of glycoproteins, although the glycosylations may be different from those found in vertebrates. In general, it is safer to use than mammalian virus as it has a limited host range and does not infect vertebrates without modifications.
=== Breastfeeding === In 2016, estimates suggested that more widespread breastfeeding could prevent about 823,000 deaths annually of children under age 5. In addition to reducing infant deaths, breast milk provides an important source of micronutrients - which are clinically proven to bolster children's immune systems – and provides long-term defenses against non-communicable and allergic diseases. Breastfeeding may improve cognitive abilities in children, and correlates strongly with individual educational achievements. As previously noted, lack of proper breastfeeding is a major factor in child mortality rates, and is a primary determinant of disease development for children. The medical community recommends exclusively breastfeeding infants for 6 months, with nutritional whole food supplementation and continued breastfeeding up to 2 years or older for overall optimal health outcomes. Exclusive breastfeeding is defined as giving an infant only breast milk for six months as a source of food and nutrition. This means no other liquids, including water or semi-solid foods.
In 2025, Medtronic was included in Forbes lists of America's Best Large Employers. In March 2026, Medtronic separated its diabetes business into MiniMed Group, Inc., which completed an initial public offering on March 9. Medtronic retained approximately 89.86% of MiniMed following the offering, while MiniMed became a separately publicly traded company on the Nasdaq. In September 2026, Medtronic launched an exchange offer as part of its planned separation of MiniMed. The offer covers up to 225,361,295 newly issued MiniMed common shares in exchange for Medtronic ordinary shares, representing approximately 80.1% of MiniMed's outstanding shares. If the exchange offer is oversubscribed, Medtronic intends to exchange additional shares of MiniMed representing its remaining interest, which would result in MiniMed becoming independent of Medtronic.The exchange offer is scheduled to expire on October 9, 2026, unless extended or terminated.
According to the American Heart Association (AHA) a chest x-ray should not be used to diagnose or assess for aortic dissections. The AHA states that chest x-rays are not adequately sensitive nor specific to accurately diagnose aortic dissections. However, certain findings on a chest x-ray may suggest an aortic dissection. These findings include: widening of the mediastinum, disruption of the normal contour of the aortic knob, the calcium sign (a separation of more than 5 mm of the calcified intimal plaque layer from the aortic wall), a "double density" seen in the aorta, and deviation of the trachea to the right.
Sources: en.wikipedia.org
=== Pregnancy === It has been found that women who consumed ≥13 mg of creatine per kg of body mass daily have a lower risk of obstetric conditions. Creatine's properties support energy for production, stabilization of maternal plasma creatine, improved pregnancy outcomes, as well as reduced oxidative stress. It was also found to reduce risk of preterm birth, support immune function, and reduce risk of perinatal brain injury. Perinatal brain injury occurs after hypoxia events, creatine allows cells to recover faster.
The first cycle is a way of synthesis of glyoxylate. During this cycle, two equivalents of bicarbonate are fixed by the action of two enzymes: the acetyl-CoA carboxylase catalyzes the carboxylation of the acetyl-CoA to malonyl-CoA and propionyl-CoA carboxylase catalyses the carboxylation of propionyl-CoA to methylamalonyl-CoA. From this point, a series of reactions lead to the formation of glyoxylate, which will thus become part of the second cycle.
=== Skin lesions === Initially red to pink, flat spots (formally, "macules") and raised bumps (formally, "papules") may be seen on the skin. Once fully developed, the classic appearance is "non-blanching, palpable purpura". This appears as deep red to purple spots that feel raised to the touch. Purpura refers to the red-purple discolored spots, while palpable implies that these spots can be felt as raised from the surrounding skin. Additionally, when gently pressed, the color does not fade to a lighter color ("non-blanching"). The red-purple color of the lesions is due to the inflammation in the blood vessels, causing red blood cells to escape into the dermis skin layer. Small fluid-filled blisters (or "vesicles"), pus-filled bumps resembling a pimple (or "pustules"), or shallow ulcers may also develop but are less common. The location of skin lesions varies, but they are most commonly found symmetrically below the waist, primarily on the buttocks and legs. Other distributions include localized areas on the upper body or over several areas of the body. With treatment, the lesions typically resolve in weeks to months and leave behind flat spots that are darker than the surrounding skin (see "Postinflammatory hyperpigmentation" on "Hyperpigmentation"). A portion of cases may be persistent or recurrent. This tends to occur when the vasculitis is associated with chronic conditions such as connective tissue diseases.
Shaw's 2014 short film SMILF, which she wrote, directed and starred in opposite Thomas Middleditch, won the 2015 Short Film Jury Award for U.S. Fiction at Sundance. In 2015, SMILF was picked up by Showtime as a half-hour comedy television show with Shaw as showrunner, writing, directing, starring in, and producing the series. The first season, which was shot on location in South Boston as well as Los Angeles, received generally positive reviews, with her portrayal of single mother Bridgette Bird notable for its realism, insight, and biting humor. "Frankie Shaw, it [SMILF] marks the arrival of an important and original voice." SMILF co-stars Connie Britton and Rosie O'Donnell, and tackles subjects like eating disorders and sexual abuse. Shaw said that the show was a way to discuss and portray the role of women on screen. In November 2017, Showtime renewed SMILF for a second season. In December 2018, it was reported that Shaw and the series had been accused of workplace misconduct. In March 2019, the series was cancelled after two seasons. In 2016, Shaw returned to the Sundance Film Festival with another short film she wrote and directed, a dark comedy titled Too Legit, which stars Zoë Kravitz, Teresa Palmer, Nate Corddry and Clark Gregg. Too Legit is inspired by a satire of Congressman Todd Akin's controversial 2012 remarks about rape and pregnancy: "It seems to be, first of all, from what I understand from doctors, [rape resulting in pregnancy is] really rare.
Sources: en.wikipedia.org
Projected to go undrafted by Sports Illustrated, who criticized his lack of "balance, body control and ability in space," Kuper was ranked as the No. 28 offensive guard available in the 2006 NFL draft. Kuper was eventually selected in the fifth round, 161st overall, by the Denver Broncos. He was the highest selected North Dakota lineman since Todd Thomas in 1981. Kuper started 79-of-90 games played (68 at right guard) while playing his entire eight-year NFL career with the Broncos. On June 4, 2010, the Broncos announced that they had signed Kuper to a five-year deal worth $25.5 million. The new contract made him the second-highest-paid offensive lineman in Broncos' history, second only to former left tackle Matt Lepsis. In 2010, the Denver Broncos announced that Kuper had been selected as co-captain of the Broncos offense, along with Kyle Orton and Daniel Graham. During the regular season finale in 2011 against the Kansas City Chiefs, Kuper suffered a gruesome broken ankle that ended his season. That season Kuper made the Pro Bowl, but withdrew due to the injury and needed surgery. A three-time captain, Kuper was recipient of the Ed Block Courage Award in 2012 as voted on by his teammates. Kuper retired on March 11, 2014.
(E)-4-Hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP or HMB-PP) is an intermediate of the MEP pathway (non-mevalonate pathway) of isoprenoid biosynthesis. The enzyme HMB-PP synthase (GcpE, IspG) catalyzes the conversion of 2-C-methyl-D-erythritol 2,4-cyclodiphosphate (MEcPP) into HMB-PP. HMB-PP is then converted further to isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) by HMB-PP reductase (LytB, IspH). HMB-PP is an intermediate in the non-mevalonate pathway for the biosynthesis of the isoprenoid precursors isopentenyl pyrophosphate and dimethylallyl pyrophosphate. Most gram-negative bacteria, the photosynthetic cyanobacteria and green algae use only this pathway, while higher plants also use the mevalonate pathway. The enzyme 4-hydroxy-3-methylbut-2-en-1-yl diphosphate synthase uses two reduced ferredoxin proteins per molecule of the precursor MEcPP to convert it to HMB-PP:
In a normal thermal reactor, tin-121m has a very low fission product yield; thus, this isotope is not a significant contributor to nuclear waste. Fast fission or fission of some heavier actinides will produce 121mSn at higher yields. For example, its yield from U-235 is 0.0007% per thermal fission and 0.002% per fast fission.
27 September Physicists report studies, for the first time, supporting the notion that antimatter particles behave in a similar way as normal matter in a gravitational field. Astronomers report studies suggesting that the rings of Saturn may have resulted from the collision of two moons "a few hundred million years ago". A breakthrough in desalination is achieved by engineers, using a solar-powered device to create freshwater at lower cost than tap water.
== See also == Lists of sequenced genomes List of sequenced bacterial genomes List of sequenced archaeal genomes List of sequenced eukaryotic genomes List of sequenced mitochondrial genomes List of sequenced plastomes List of sequenced animal mitochondrial genomes List of sequenced fungi genomes List of sequenced fungi mitochondrial genomes List of sequenced plant genomes List of sequenced plant mitochondrial genomes List of sequenced protist genomes
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.
Reverse-phase HPLC is the usual method and gives a percentage purity value. Mass spectrometry then confirms the molecular mass. Together they provide a basic identity and purity profile for a lot.