A practical reference on Pro-Gly-Pro: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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.
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.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Calculated for the free peptide |
| Molecular weight | About 751.9 g/mol | Derived from the sequence |
| Appearance | White to off-white powder | Typical lyophilised form |
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.
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.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
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.
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.
=== Pollution and phytoremediation === EcM fungi have been found to have beneficial effects in several types of polluted environments, including: • High salt: A number of studies have shown that certain EcM fungi can help their hosts survive high soil salinity conditions. • Radionuclides: Many species of ectomycorrhizal fungi, including the Cortinariaceae, can hyperaccumulate radionuclides • Organic pollutants: Some EcM species are capable of decomposing persistent organic pollutants (POPs) such as organochlorides and polychlorinated biphenyls (PCBs). Chemicals that can be detoxified by EcM fungi, either alone or in association with their host plant, include 2,4-dichlorophenol and tetrachloroethylene.
Half-Life 2: Episode Three is a canceled first-person shooter game developed by Valve. It was planned as the last in a trilogy of episodic games continuing the story of Half-Life 2 (2004). Valve announced Episode Three in May 2006, with a release planned for 2007. Following the cliffhanger ending of Episode Two (2007), it was widely anticipated. Episode Three was to be set in the Arctic and introduce elements such as an ice gun and a blob-like enemy. Marc Laidlaw, the writer for the Half-Life series, intended it to end the Half-Life 2 story arc. Little information was released over the following years, and in 2011 Wired described it as vaporware. Valve eventually canceled Episode Three as they had become fatigued with Half-Life and could not settle on a direction. Additionally, they wanted to create more ambitious games and felt limited by the episodic format. They delayed development of a new Half-Life game until their new game engine, Source 2, was complete. Laidlaw left Valve in 2016. In 2017, he released a short story that journalists speculated was a summary of the Episode Three plot. In response, fans launched projects attempting to recreate Episode Three. After canceling several further Half-Life games, Valve released a virtual reality game, Half-Life: Alyx, in 2020.
Work has also been done for long-chain fatty acids and found that even-numbered sites, which are thought to be derived from C2 position of the acetyl group, are more enriched in 2H than odd-numbered hydrogen that come from C1 position of the acetyl group. Duan et al. reported a strong KIE during the desaturation from oleic acid to linoleic acid. In summary, the underlying physics of SNIF-NMR enables it to measure isotopomers. Another advantage of NMR measurement over mass spectrometry is that it analyzes samples non-destructively. 2H SNIF-NMR has been well industrialized in source identification and forensics, and has contributed much to biochemical pathway studies. The application of 2H SNIF-NMR to geological records is sporadic and still needs exploring.
Sources: en.wikipedia.org
On 15 May, an armed mob, headed by François-Vincent Raspail, Auguste Blanqui, and Armand Barbès, and assisted by the proletariat-aligned Guard, attempted to overwhelm the Assembly, but were defeated by the bourgeois-aligned battalions of the National Guard. Meanwhile, the national workshops were unable to provide remunerative work for the genuine unemployed, and of the thousands who applied, the greater number were employed in aimless digging and refilling of trenches; soon even this expedient failed, and those for whom work could not be invented were given a half wage of 1 franc a day. On 21 June, Alfred de Falloux decided in the name of the parliamentary commission on labour that the workmen should be discharged within three days and those who were able-bodied should be forced to enlist in the armed forces.
In all the places where they pretend to have the graveclothes, they show a large piece of linen by which the whole body, including the head, was covered, and, accordingly, the figure exhibited is that of an entire body. But the Evangelist John relates that Christ was buried, "as is the manner of the Jews to bury". What that manner was may be learned, not only from the Jews, by whom it is still observed, but also from their books, which explain what the ancient practice was. It was this: The body was wrapped up by itself as far as the shoulders, and then the head by itself was bound round with a napkin, tied by the four corners, into a knot. And this is expressed by the Evangelist, when he says that Peter saw the linen clothes in which the body had been wrapped lying in one place, and the napkin which had been wrapped about the head lying in another. The term napkin may mean either a handkerchief employed to wipe the face, or it may mean a shawl, but never means a large piece of linen in which the whole body may be wrapped. I have, however, used the term in the sense which they improperly give to it. On the whole, either the Evangelist John must have given a false account, or every one of them must be convicted of falsehood, thus making it manifest that they have too impudently imposed on the unlearned. Although pieces said to be of burial cloths of Jesus are held by at least four churches in France and three in Italy, none has gathered as much religious following as the Shroud of Turin.
== National variants == Similar meat and pastry recipes include the Czech klobásník, the Belgian worstenbroodje, the Dutch saucijzenbroodje, the German Münsterländer Wurstbrötchen and sausage bread in the United States. Hong Kong has developed its own style of sausage roll. Instead of having sausage meat wrapped in puff pastry like the traditional Western style, the Hong Kong style "sausage bun" (Chinese: 腸仔包) consists of a sausage wrapped inside a soft milk bread style bun.
Sources: en.wikipedia.org
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.
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.
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.
Reports describe modulation of GABA signalling, changes in monoamine turnover and effects on neurotrophic factor expression. These observations come mainly from animal and cell studies. A single unifying mechanism has not been demonstrated.