The short version of Pro-Gly-Pro fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-05-19 and is reviewed periodically as new material appears.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Derived from the seven-residue sequence |
| Molecular weight | About 751.9 g/mol | Average mass; the monoisotopic value is slightly lower |
| Residue count | Seven amino acids | Thr-Lys-Pro-Arg-Pro-Gly-Pro |
| Parent compound | Tuftsin (Thr-Lys-Pro-Arg) | Selank extends tuftsin at the C-terminus |
| Compound class | Synthetic short peptide | Studied in a research setting; not a licensed drug in most markets |
Reversed-phase high-performance liquid chromatography is the standard technique for estimating peptide purity. The result is a peak-area percentage, which describes how much of the detected material elutes as the main peak in one run. Mass spectrometry confirms the molecular mass and can reveal truncated, adducted, or otherwise modified species. Amino acid analysis or tandem mass spectrometry can address sequence fidelity when identity is in doubt. None of these measurements, taken alone, establishes that a sample is fit for any specific purpose.
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
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.
==== March ==== On 1 March, clashes broke out between Syrian caretaker government forces and local Druze armed groups responsible for community protection in Jaramana, during the security operation launched by Syrian authorities on the suburb. Members of the Jaramana Shield Brigade were involved in the clashes. During a violent altercation which erupted in Al-Seuof Square between two General Security Service members and local armed residents, one local gunman sustained serious injuries, requiring hospitalization, while authorities took the two security personnel into custody. In the clash at Al-Seuof Square, the wounded local gunman was taken to Al-Mujtahed Hospital for medical treatment. But Hay'at Tahrir al-Sham militants arrived at the hospital where the situation escalated when one of the wounded man's escorts allegedly made blasphemous remarks about Allah. This prompted members of Hayat Tahrir al-Sham present at the hospital to physically assault and subsequently detain the companions, resulting in one confirmed fatality among security forces. The clashes ended on 2 March 2025, after the entry of General Security Service into Jaramana. A meeting was held in March 2025 between Druze spiritual leader Hikmat al-Hijri, Yahya Al-Hajjar, the head of the Men of Dignity, Suleiman Abdul Baqi, the leader of Ahrar Jabal al-Arab, and Shakib Azam, the leader of Al-Jabal Brigade, in which it was agreed that the General Security Service would be "re-activated" in the governorate, as long as the people involved were from Suwayda.
Polydeoxyribonucleotide (PDRN), is a mixture of single-stranded oligonucleotides with weight ranging from approximately 50 kDa to 1500 kDa, peaking around 350kDa in some commercial forms. PDRN was originally isolated from human placenta for potential pharmaceutical applications in Italy, but it is now obtained by fractionating and purifying DNA extracted from salmon or trout sperm. Novel sources of PDRN are being further studied but salmon or trout sperm cells are more commonly used as they are easily processed and readily available DNA source. PDRN has anti-inflammatory effects, stimulates collagen production and promotes angiogenesis, and is mainly used in pharmaceutical applications with purported anti-wrinkle and anti-aging effects. Additionally, it has shown improvement and acceleration of wound healing and tissue repair, demonstrated in treatment of tendinopathy and diabetic foot ulcers. The mechanism involves activation of adenosine A2A receptors, upregulating expression of vascular endothelial growth factor (VEGF), and stimulation of the DNA salvage pathway.
Pathology Laboratory Clinical Biology Laboratory Virology Laboratory Parasitology Laboratory Clinical Microbiology Laboratory Immunology Unit Data Center Administration The INRB is based at Avenue de la Démocratie (formerly Avenue des Huileries), BP 1197, Kinshasa-Gombe, DRC.
=== Oxidative stress === Numerous whole-exome sequencing studies have demonstrated that vitiligo is associated with polymorphisms in genes involved in the response to oxidative stress, supporting the association of elevated levels of reactive oxygen species in melanocytes with the induction of an autoimmune response. Thus, diseases presenting with altered mitochondrial function such as MELAS, Vogt–Koyanagi–Harada and Kabuki syndrome are associated with an increased risk of vitiligo. In line with these observations, genetic alterations in mitochondrial DNA (mtDNA) of melanocytes associated with altered mitochondrial function lead to a release of mtDNA that can be detected in the skin of vitiligo patients. This mtDNA can be sensed by the cGAS–STING pathway, resulting in pro-inflammatory cytokine and chemokine production promoting the recruitment of cytotoxic T cells.
Sources: en.wikipedia.org
== Role in the body == Scientific research highlights numerous therapeutic and health-promoting properties of 1-MNA, including vascular protective, anticoagulant, anti-atherosclerotic, anti-inflammatory, neuroprotective, and endurance-enhancing effects.
At least 90% of smallpox cases among unvaccinated persons were of the ordinary type. In this form of the disease, by the second day of the rash the macules had become raised papules. By the third or fourth day, the papules had filled with an opalescent fluid to become vesicles. This fluid became opaque and turbid within 24–48 hours, resulting in pustules. By the sixth or seventh day, all the skin lesions had become pustules. Between seven and ten days the pustules had matured and reached their maximum size. The pustules were sharply raised, typically round, tense, and firm to the touch. The pustules were deeply embedded in the dermis, giving them the feel of a small bead in the skin. Fluid slowly leaked from the pustules, and by the end of the second week, the pustules had deflated and began to dry up, forming crusts or scabs. By day 16–20 scabs had formed over all of the lesions, which had started to flake off, leaving depigmented scars. Ordinary smallpox generally produced a discrete rash, in which the pustules stood out on the skin separately. The distribution of the rash was most dense on the face, denser on the extremities than on the trunk, and denser on the distal parts of the extremities than on the proximal. The palms of the hands and soles of the feet were involved in most cases.
In August 2015, Arby's introduced a series of five small sandwiches called Sliders starting at $1.29, with prices varied by location. These new menu items led to an increase in sales at many locations. This is not the first time Arby's tried to market miniature sandwiches. Two years earlier, Arby's tried to sell a similar product called the Mighty Minis that were sold in pairs. During the first month of national sales, the firm was able to sell 1 million or a ton of sliders. To encourage additional sales outside normal lunch and dinner meal hours, began to offer sliders and small size drinks and sides at the reduced price of $1 between the hours of 2 and 5 p.m. starting in October 2015. Due to Arby's great success in the increase of sales created by the introduction of this new product line, Nation's Restaurant News awarded Arby's its MenuMasters Award for 2016. The Turkey 'n Cheese was initially offered as a limited time menu item in December 2016 but was shown to be popular enough to be retained on the regular menu. A Pizza Slider was introduced as a limited time menu item in May 2017. In late August 2016, Arby's introduced four chicken sandwiches that used a buttermilk-based breaded breast filet. Arby's debuted a new sandwich known as Smokehouse Pork Belly Sandwich in October 2016.
=== Clinical trials === In addition to the increased production at the Dunn School, commercial production from a pilot plant established by Imperial Chemical Industries became available in January 1942, and Kembel, Bishop and Company delivered its first batch of 200 imperial gallons (910 L) on 11 September. Florey conducted a second series of clinical trials. Ethel was placed in charge, but while Florey was a consulting pathologist at Oxford hospitals and therefore entitled to use their wards and services, Ethel, to his annoyance, was accredited merely as his assistant. Doctors tended to refer patients to the trial who were in desperate circumstances rather than those who were the most suitable candidates for treatment, but when penicillin did succeed anyway, confidence in its efficacy rose. Harry Lambert, a friend of Fleming's dying from a meningococcal infection, became the twelfth case on 5 August 1942. He survived, but someone at St. Mary's Hospital leaked the result to the press, resulting in an editorial in The Times on 27 August. Florey was appalled; this could only create a public demand for penicillin when all available supplies were needed for the clinical trials. On 25 September, Florey met with Sir Cecil McAlpine Weir, the Director-General of Equipment and Stores at the Ministry of Supply, who promised overriding priority for the mass production of penicillin. Ethel and Howard Florey published the results of clinical trials of 187 cases of treatment with penicillin in The Lancet on 27 March 1943.
Acanthosis nigricans-muscle cramps-acral enlargement syndrome, also known as Acanthosis nigricans-insulin resistance-muscle cramps-acral enlargement syndrome, is an extremely rare genetic disorder which is characterized by the appearance of acanthosis nigricans, insulin resistance, muscle cramps of severe intensity, and acral hypertrophy/enlargement. Only 2 cases have been reported in medical literature. It was first discovered when Jeffrey Flier and his colleagues described two siblings of the opposite sex with the symptoms mentioned above. (plus: large, chunky hands), the sister had virilized polycystic ovaries. After being treated with dilantin, the cramps' severity lowered and the brother's insulin resistance also lowered. The inheritance pattern of this disorder is thought to be autosomal recessive.
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.
Tuftsin contains four residues, while selank carries an additional Pro-Gly-Pro segment at the carboxyl end. That extension is intended to reduce enzymatic cleavage. Comparative pharmacokinetic data in humans remain limited.
No single receptor target is widely accepted as the definitive mediator of the reported effects. Proposed contributors include GABAergic modulation, shifts in monoamine turnover, and altered neuropeptide degradation. The mechanism is treated in the literature as unresolved.
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.