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Identity And Structural Background — What the Evidence Shows

By Editorial Desk · published 2026-04-03 · last reviewed 2026-05-04 · News

A practical reference on tuftsin: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.

Reviewed 2026-05-04. Anything still debated is marked as such rather than presented as settled.

Identity and Structural Background

Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.

Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.

Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.

Mechanism and Evidence Base

Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.

Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.

Selank at a glance

PropertyValueNotes
Chemical classSynthetic heptapeptideTuftsin analogue
SequenceThr-Lys-Pro-Arg-Pro-Gly-ProSingle-letter form: TKPRPGP
Molecular formulaC33H57N11O9Calculated for the free peptide
Molecular weightAbout 751.9 g/molDerived from the sequence
AppearanceWhite to off-white powderTypical lyophilised form

Analytical Methods and Material Handling

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.

Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.

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Selank Origin and Chemical Identity

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.

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.

Reference notes

"Just ahead of our time again!" jests Hoffmann. Despite the more commercially appealing sound of the album, it fell short of the sales figures of its predecessor Balls to the Wall in America. Udo remembers the Breaker through Metal Heart era as the time when the band got along best together. Thus this would turn out to be the last album of Accept's golden era, as cracks were soon to appear in the band's solidarity. The 2002 digitally remastered CD edition includes two live bonus tracks, "Love Child" and "Living for Tonite", both taken from the live EP Kaizoku-Ban. The 2013 release from UK-based record label Hear No Evil Recordings contains the live EP itself.

== Plasmid preparation == Chloramphenicol is often used when growing E. coli cultures intended for plasmid preparation. Chloramphenicol halts protein synthesis, but allows plasmids with a relaxed origin of replication to keep replicating, thus improving yield.

== Medical relevance == Genetic PGLYRP2 variants or changed expression of PGLYRP2 are associated with some diseases. Patients with inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis, have significantly more frequent missense variants in PGLYRP2 gene (and also in the other three PGLYRP genes) than healthy controls. These results suggest that PGLYRP2 protects humans from these inflammatory diseases, and that mutations in PGLYRP2 gene are among the genetic factors predisposing to these diseases. PGLYRP2 variants are also associated with esophageal squamous cell carcinoma and Parkinson's disease. Increased serum PGLYRP2 levels are present in patients with systemic lupus erythematosus (and correlate with disease activity index, renal damage, and abnormal lipid profile), chronic hepatitis B virus infection, myocardial infarction, and coronary artery disease (and correlate with the severity of the disease). Decreased expression of PGLYRP2 is found in HIV-associated tuberculosis, drug-sensitive tuberculosis, Lyme disease, hepatocellular carcinoma, and polyarteritis nodosa. Autoantibodies to PGLYRP2 are significantly increased in patients with rheumatoid arthritis.

=== Contacts with scientists abroad === Between the 1950s and the 1970s, Hodgkin established and maintained lasting contacts with scientists in her field abroad—at the Institute of Crystallography in Moscow; in India; and with the Chinese group working in Beijing and Shanghai on the structure of insulin. Her first visit to China was in 1959. Over the next quarter century, she travelled there seven more times, the last visit a year before her death. Particularly memorable was the visit in 1971 after the Chinese group themselves independently solved the structure of insulin, later than Hodgkin's team but to a higher resolution. During the subsequent three years, 1972–1975, when she was President of the International Union of Crystallography she was unable to persuade the Chinese authorities, however, to permit the country's scientists to become members of the Union and attend its meetings. Her relations with a supposed scientist in another "People's Democracy" had less happy results. At the age of 73, Hodgkin wrote a foreword to the English edition of Stereospecific Polymerization of Isoprene, published by Robert Maxwell as the work of Elena Ceaușescu, wife of Romania's communist dictator. Hodgkin wrote of the author's "outstanding achievements" and "impressive" career. Following the overthrow of Ceausescu during the Romanian Revolution of 1989, it was revealed that Elena Ceausescu had neither finished secondary school nor attended university.

Sources: en.wikipedia.org

Reference notes

== History == Scott Reismanis, a website developer from Melbourne, Australia, first pursued web development as a hobby, creating two websites dedicated to video games. Afterwards, he purchased the ChaosRealm.com domain and formed the Realm Network. The network comprised over twenty websites, one of which was ModDB's predecessor, ModRealm. Launched in 1998, ModRealm was initially dedicated to Counter-Strike cheat codes before becoming a modding website. The website became defunct in December 2001, when its network was shut down after its hosting service, Playnet, filed for bankruptcy. Reismanis was motivated to start a new website by the difficulty of searching for mods on the then-dominant search engine, AltaVista, much less mods released to the public. He began ModDB's development in January 2002, following IMDb's structure in the process. The website was launched as Mod Database in June 2002. It differed from his earlier websites in that its articles were managed by the community, not only the website's founder. By January 2005, ModDB listed 49,539 members and 2,191 mods. In 2006, the ModDB team launched AddonDB, whose aim was to list additional content for games not applicable under the category of game modifications. This includes models, skins and maps. Just one year into service, it was merged into ModDB.

== History == AbbVie was formed in 2012 as a corporate spin-off from Abbott Laboratories. It became a public company in January 2013. In January 2014, the company acquired ImmuVen, a startup incubated at the University of Illinois Urbana-Champaign and focused on biotherapeutics to treat cancer, infectious disease, and autoimmune disorders. In September 2014, AbbVie and Infinity Pharmaceuticals entered into a collaboration to develop and commercialize duvelisib, Infinity's PI3K inhibitor for the treatment of patients with cancer. On the same day, AbbVie and Calico entered into a research and development (R&D) collaboration intended to discover, develop and bring to market new therapies for patients with aging-associated diseases including neurodegeneration and cancer. California Life Company, operating as Calico, is an Alphabet Inc. subsidiary focused on aging and age-related diseases, and led by former Genentech chairman and CEO of Arthur D. Levinson and former Genentech EVP and chief medical officer Hal V. Barron (who subsequently left the company). In October 2014, AbbVie ended its efforts to acquire Shire, which would have been one of the largest mergers and acquisitions (M&A) deals of that year and one of the largest tax inversions in history, due to changes in the US tax code by the US Treasury; AbbVie had to pay a $1.6 billion breakup fee. In May 2015, AbbVie acquired oncology firm Pharmacyclics and its treatment for blood cancers, ibrutinib; AstraZeneca had also been bidding to acquire Pharmacyclics.

King Crimson have been described musically as progressive rock, art rock, and post-progressive, with their earlier works being described as proto-prog. Their music was initially grounded in the rock of the 1960s, especially the acid rock and psychedelic rock movements. The band played Donovan's "Get Thy Bearings" in concert, and were known to play the Beatles' "Lucy in the Sky with Diamonds" in their rehearsals. However, for their own compositions, King Crimson (unlike the rock bands that had come before them) largely stripped away the blues-based foundations of rock music and replaced them with influences derived from classical composers. The first incarnation of King Crimson played the Mars section of Gustav Holst's suite The Planets live and later the band used Mars as a foundation for the song "Devil's Triangle". As a result of this influence, In the Court of the Crimson King is frequently viewed as the nominal starting point of the progressive rock movements. King Crimson also initially displayed strong jazz influences, especially on its signature track "21st Century Schizoid Man". The band also drew on English folk music for compositions such as "Moonchild" and "I Talk to the Wind". In the 1972 lineup, Fripp's intention was to combine the music of Jimi Hendrix, Igor Stravinsky and Béla Bartók. The 1981 reunion of the band brought in even more elements, displaying the influence of funk, post-punk, new wave, gamelan music and minimalist classical composers such as Philip Glass, Steve Reich and Terry Riley.

Sources: en.wikipedia.org

Frequently asked questions

What is the peptide sequence of Selank?

The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, commonly written as TKPRPGP. It shares the first four residues with tuftsin and carries three prolines in the chain. The proline-rich tail is the main structural feature that separates it from the parent tetrapeptide.

How is it related to tuftsin?

Selank is a synthetic analogue built on the tuftsin tetrapeptide Thr-Lys-Pro-Arg. Extra proline residues were added to the C-terminus during design work. That modification is intended to make the peptide less vulnerable to rapid enzymatic degradation.

Why do different sources use different names?

Transliteration from Russian produces variant spellings such as Selanc. Many suppliers avoid the trade-style name entirely and list the peptide sequence. Comparing sequences rather than names is the reliable way to confirm two entries describe the same molecule.

What mechanisms are proposed for Selank?

Reports describe effects on GABA-A receptor expression, monoamine turnover, and neurotrophic factor levels. These are proposed mechanisms drawn mainly from animal models. No single molecular target has been established.

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