Pro-Gly-Pro comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-07-20. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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 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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analog of the tetrapeptide tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Reported consistently across pharmacopoeial descriptions |
| Appearance | White to off-white lyophilized powder | Typical form of research-grade material |
| Solubility | Freely soluble in water | Aqueous buffers; poor in nonpolar solvents |
| Typical storage temperature | -20 degrees Celsius | Lyophilized powder; protect from moisture |
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.
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.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
17α-OHP is the parent compound of a class of progestins referred to as the 17α-hydroxyprogesterone derivatives. Among others, this class of drugs includes chlormadinone acetate, cyproterone acetate, hydroxyprogesterone caproate, medroxyprogesterone acetate, and megestrol acetate.
In DNA, fraying occurs when non-complementary regions exist at the end of an otherwise complementary double-strand of DNA. However, branched DNA can occur if a third strand of DNA is introduced and contains adjoining regions able to hybridize with the frayed regions of the pre-existing double-strand. Although the simplest example of branched DNA involves only three strands of DNA, complexes involving additional strands and multiple branches are also possible. Branched DNA can be used in nanotechnology to construct geometric shapes, see the section on uses in technology below.
== Types of warfare == Cyber warfare can present a multitude of threats towards a nation. At the most basic level, cyber attacks can be used to support traditional warfare. For example, tampering with the operation of air defenses via cyber means in order to facilitate an air attack. Aside from these "hard" threats, cyber warfare can also contribute towards "soft" threats such as espionage and propaganda. Eugene Kaspersky, founder of Kaspersky Lab, equates large-scale cyber weapons, such as Flame and NetTraveler which his company discovered, to biological weapons, claiming that in an interconnected world, they have the potential to be equally destructive.
Sources: en.wikipedia.org
=== EC 1.4.1 With NAD+ or NADP+ as acceptor === EC 1.4.1.1: alanine dehydrogenase EC 1.4.1.2: glutamate dehydrogenase EC 1.4.1.3: glutamate dehydrogenase (NAD(P)+) EC 1.4.1.4: glutamate dehydrogenase (NADP+) EC 1.4.1.5: L-amino-acid dehydrogenase EC 1.4.1.6: deleted, Now included with EC 1.21.4.1, D-proline reductase (dithiol) EC 1.4.1.7: serine 2-dehydrogenase EC 1.4.1.8: valine dehydrogenase (NADP+) EC 1.4.1.9: leucine dehydrogenase EC 1.4.1.10: glycine dehydrogenase EC 1.4.1.11: L-erythro-3,5-diaminohexanoate dehydrogenase EC 1.4.1.12: 2,4-diaminopentanoate dehydrogenase EC 1.4.1.13: glutamate synthase (NADPH) EC 1.4.1.14: glutamate synthase (NADH) EC 1.4.1.15: lysine dehydrogenase EC 1.4.1.16: diaminopimelate dehydrogenase EC 1.4.1.17: N-methylalanine dehydrogenase EC 1.4.1.18: lysine 6-dehydrogenase EC 1.4.1.19: tryptophan dehydrogenase EC 1.4.1.20: phenylalanine dehydrogenase EC 1.4.1.21: aspartate dehydrogenase EC 1.4.1.22: there is no overall consumption of NAD+ during the reaction. As a result, transfer of the enzyme from EC 4.3.1.12 was not necessary and EC 1.4.1.22 was withdrawn before being made official EC 1.4.1.23: valine dehydrogenase (NAD+) EC 1.4.1.24: 3-dehydroquinate synthase II EC 1.4.1.25: L-arginine dehydrogenase EC 1.4.1.26: 2,4-diaminopentanoate dehydrogenase (NAD+) EC 1.4.1.27: glycine cleavage system
Clivo-Axial Angle equal or less than 135 degrees Grabb-Oakes measurement equal or greater than 9 mm Harris measurement greater than 12 mm Spinal subluxation Alternatively, craniocervical instability can be diagnosed if a trial of cervical traction, typically using a halo fixation device, results in a significant alleviation of symptoms.
Given its conservation throughout evolution, the action potential seems to confer evolutionary advantages. One function of action potentials is rapid, long-range signaling within the organism; the conduction velocity can exceed 110 m/s, which is one-third the speed of sound. For comparison, a hormone molecule carried in the bloodstream moves at roughly 8 m/s in large arteries. Part of this function is the tight coordination of mechanical events, such as the contraction of the heart. A second function is the computation associated with its generation. Being an all-or-none signal that does not decay with transmission distance, the action potential has similar advantages to digital electronics. The integration of various dendritic signals at the axon hillock and its thresholding to form a complex train of action potentials is another form of computation, one that has been exploited biologically to form central pattern generators and mimicked in artificial neural networks. The common prokaryotic/eukaryotic ancestor, which lived perhaps four billion years ago, is believed to have had voltage-gated channels. This functionality was likely, at some later point, cross-purposed to provide a communication mechanism. Even modern single-celled bacteria can utilize action potentials to communicate with other bacteria in the same biofilm.
Alpha Oumar Barry – Medical doctor and politician, former Minister of State for Exchange, Guinea Folly Bah Thibault - French Guinean journalist, and senior presenter for Al Jazeera English, Founder of Elle Ira à l’Ecole. Ousmane Baldé – Economist and politician. former governor of Guinean Fed reserve (Central bank), former minister of finance. Guinea M'Mahawa Sylla - First female general of the Guinean Armed Forces, Governor of Conakry. Khaité Sall (in French - Minister of Health, Guinea Kaba Rougui Barry - Minister of Pre-University, Technical, Vocational Education and Civic Education, Mayor of Matam, first female mayor in Guinea. Aissatou Baldé - former minister of youth and youth employment. Moustapha Mamy Diaby - former Minister of Mail, Telecommunications and the digital Economy, Guinea. Mamadou Boye Bah – Politician and economist, former president of Union for the New Republic and former president of Union of Democratic Forces of Guinea. Siradiou Diallo – Journalist and politician, former magazine Jeune Afrique Editor in chief, and former president of Union for Progress and Renewal (Guinea). Cellou Dalein Diallo – Economist and politician, former Minister and prime minister; Opposition Leader, Guinea Tierno Monénembo (real name Thierno Saidou Diallo) – novelist and biochemist, winner of the Prix Renaudot award in 2008 for his novel The King of Kahel, winner of Grand Prix de la Francophonie 2017. Guinea Djibril Tamsir Niane – Guinean historian, playwright and short story writer. Alpha Bacar Barry - Minister of Higher Education, Scientific Research and Innovation.
Sources: en.wikipedia.org
Selank is a synthetic seven-amino-acid peptide modeled on tuftsin, a fragment of the immunoglobulin G heavy chain. It was designed in Russia to combine anxiolytic and immunomodulatory properties in one molecule.
The first four residues of Selank reproduce the tuftsin sequence Thr-Lys-Pro-Arg. A Pro-Gly-Pro extension at the C-terminus was added to slow enzymatic breakdown and extend residence time.
It holds marketing authorization in Russia, where nasal drop formulations are sold. No equivalent approval exists in the European Union, the United States, or most other countries.
Selank is a seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.