This is a working overview of Pro-Gly-Pro, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-06-28. Anything still debated is marked as such rather than presented as settled.
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 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.
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.
| 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 |
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.
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.
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.
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.
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.
=== Venous ulcers === Venous ulcers are persistent ankle or lower leg wounds that become open. A 2024 meta-analysis reported a positive effect on the size of ulcers as well as complete healing time for venous ulcers compared to standard treatments. A study combining a PRP therapy with conventional venous ulcer treatments reported improved quality of life and healing time. "In terms of safety, the recurrence rate in the PRP group was significantly lower than that in the control group, while the rates of infection and irritative dermatitis showed no significant difference from the control group."
In 1944, Jones became the first Black-American to become a member of the American Society of Refrigeration Engineers. 1953 Merit Award, Phyllis Wheatley Auxiliary (Phillis Wheatley Club of Cleveland, Ohio), "for outstanding achievements which serve as an inspiration to youth." In 1977, he was posthumously inducted into the Minnesota Inventors Hall of Fame. In 1991, the National Medal of Technology was awarded to Joseph A. Numero and Frederick M. Jones. President George Bush presented the awards posthumously to their widows at a ceremony in the White House Rose Garden. Jones was the first Black American to receive the award. In 1996, the Thermo King Model 'C' refrigeration unit, the world's first front-mount refrigeration unit for mobile trucks, was designated an International Mechanical Engineering Landmark by the American Society of Mechanical Engineers. Jones designed and built the prototype from junkyard salvage. The challenges were to build a structural frame and refrigerant tubing connections that would withstand the constant pounding of road vibrations. In 2007, Jones was inducted into the National Inventors Hall of Fame, which honored him as a "Visionary Veteran." In the March 2009 issue of Heavy Duty Truck magazine, editor Tom Berg dubbed Jones "The King of Cool", and wrote that his "technological breakthrough redefined the global marketplace, with cultural reverberations felt from the world's largest cities to its most isolated villages." In 2015, Jones' achievements were recognized by the creators of a Black heritage-themed playground located in Minneapolis.
== Early life and education == Freeman was born on June 1, 1937, in Memphis, Tennessee. He is the son of Mamie Edna (née Revere; 1912–2000), a teacher, and Morgan Porterfield Freeman (July 6, 1915 – April 27, 1961), a barber, who died of cirrhosis in 1961. He has three older siblings. Some of Morgan's great-great-grandparents were slaves who migrated from North Carolina to Mississippi. He later discovered that his white maternal great-great-grandfather had lived with and was buried beside Freeman's black great-great-grandmother in the segregated South, as the two could not legally marry at the time. A DNA test suggested that among all of his African ancestors, a little over one-quarter came from the area that stretches from present-day Senegal to Liberia and three-quarters came from the Congo-Angola region. As an infant, Freeman was sent to his paternal grandmother in Charleston, Mississippi. He moved frequently during his childhood, living in Greenwood, Mississippi, Gary, Indiana, and finally Chicago. He made his acting debut aged nine, playing the lead role in a school play. He then attended Broad Street High School, a building which serves today as Threadgill Elementary School in Greenwood. At the age of 12, he won a statewide drama competition, and while settling into school, discovered music and theater. When Freeman was 16 years old, he contracted pneumonia. Freeman graduated from high school in 1955, but turned down a partial drama scholarship from Jackson State University, opting instead to enlist in the United States Air Force.
Under Appendix I of CITES (the Convention on International Trade in Endangered Species), commercial international trade of Komodo dragon skins or specimens is prohibited. Despite this, there are occasional reports of illegal attempts to trade in live Komodo dragons. The most recent attempt was in March 2019, when Indonesian police in the East Java city of Surabaya reported that a criminal network had been caught trying to smuggle 41 young Komodo dragons out of Indonesia. The plan was said to include shipping the animals to several other countries in Southeast Asia through Singapore. It was hoped that the animals could be sold for up to 500 million rupiah (around US$35,000) each. It was believed that the Komodo dragons had been smuggled out of East Nusa Tenggara province through the port at Ende in central Flores. In 2013, the total population of Komodo dragons in the wild was assessed as 3,222 individuals, declining to 3,092 in 2014 and 3,014 in 2015. Populations remained relatively stable on the bigger islands (Komodo and Rinca), but decreased on smaller islands, such as Nusa Kode and Gili Motang, likely due to diminishing prey availability. On Padar, a former population of Komodo dragons has recently become extirpated, of which the last individuals were seen in 1975. It is widely assumed that the Komodo dragon died out on Padar following a major decline of populations of large ungulate prey, for which poaching was most likely responsible.
Sources: en.wikipedia.org
=== Reverse genetic system === The reverse genetics system to rescue Sendai virus was created and published in 1995. Since then a number of modifications and improvements were described for representatives of Mononegavirales, Paramyxoviridae in general, and for Sendai virus in particular. The entire length of the vector SeV genome, including transgenes, has to be arranged in multiples of six nucleotides (the so-called "rule of six").
The modern practice of pathology is divided into a number of subdisciplines within the distinct but deeply interconnected aims of biological research and medical practice. Biomedical research into disease incorporates the work of a vast variety of life science specialists, whereas, in most parts of the world, to be licensed to practice pathology as a medical specialty, one has to complete medical school and secure a license to practice medicine. Structurally, the study of disease is divided into many different fields that study or diagnose markers for disease using methods and technologies particular to specific scales, organs, and tissue types.
The explosive trace detectors utilizing AFPs, known as Fido Explosives Detectors, were originally developed under the Defense Advanced Research Projects Agency (DARPA) Dog’s Nose program and is now produced by FLIR Systems. The current generation, provides broad-band trace explosive detection and weighs less than 3 lbs. The sensitivity is in the order of femtogram (1 × 10−15 grams). This is the only such technology in the field that can achieve such sensitivity.
Sources: en.wikipedia.org
== Music and lyrics == With songs written primarily on the road, the material is darker than Facelift. "We did a lot of soul searching on this album. There's a lot of intense feelings." Cantrell said, "We deal with our daily demons through music. All of the poison that builds up during the day we cleanse when we play". Drug use was front and center as a lyrical theme on the album. Three tracks ("Junkhead", "God Smack", and "Hate to Feel") specifically reference heroin use and its effects. Staley revealed that the album is semi-conceptual and that there are two basic themes in it. The first theme is about "dealing with kind of a personal anguish and turmoil, which turns into drugs to ease that pain, and being confident that that was the answer in a way. Then later on the songs start to slip down closer and closer to hell, and then he figures out that drugs were not, and are not, the way to ease that pain. Basically, it's the whole story of the last three years of my life." Staley described the other theme as being about "painful relationships and involvements with persons." Staley later expressed regret about the lyrical content of some songs on Dirt, explaining, "I wrote about drugs, and I didn't think I was being unsafe or careless by writing about them ... I didn't want my fans to think that heroin was cool. But then I've had fans come up to me and give me the thumbs up, telling me they're high. That's exactly what I didn't want to happen." Cantrell said in 2013: "That darkness was always part of the band, but it wasn't all about that.
== Service == Mrksich has also been active in serving the scientific community in a number of roles. These include his current service as the Scientific Director of the Searle Scholars Program, as a member of the Board of Governors for Argonne National Laboratory, and as a member of the Board of Directors for the Camille & Henry Dreyfus Foundation. His past appointments include service and chairing DARPA’s Defense Sciences Research Council and many program advisory committees.
== Haas atomic model == In 1910, Arthur Erich Haas proposed a model of the hydrogen atom with an electron circulating on the surface of a sphere of positive charge. The model resembled Thomson's plum pudding model, but Haas added a radical new twist: he constrained the electron's potential energy,
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.
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.