If you have been reading about peptidase and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2025-09-06. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
| 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 |
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.
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.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
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.
Mass spectrometry produces various types of data. The most common data representation is the mass spectrum. Certain types of mass spectrometry data are best represented as a mass chromatogram. Types of chromatograms include selected ion monitoring (SIM), total ion current (TIC), and selected reaction monitoring, among many others. Other types of mass spectrometry data are well represented as a three-dimensional contour map. In this form, the mass-to-charge, m/z is on the x-axis, intensity the y-axis, and an additional experimental parameter, such as time, is recorded on the z-axis.
The Druze strictly avoid iconography, but use five colors ("Five Limits" خمس حدود khams ḥudūd) as a religious symbol: green, red, yellow, blue, and white. The First limit (green), identified by Ismail at-Tamimi (d. 1030) in the Epistle of the Candle, represents either Hamza Ibn Ali or Jesus, symbolizing the "Universal Mind/Intelligence/Nous".
== Scope and funding == As of 2021, the FDA had responsibility for overseeing $2.7 trillion in food, medical, and tobacco products. Some 54% of its budget derives from the federal government, and 46% is covered by industry user fees for FDA services. For example, pharmaceutical firms pay fees to expedite drug reviews. According to Forbes, pharmaceutical firms provide 75% of the FDA's drug review budget.
The BioBricks assembly standard was described and introduced by Tom Knight in 2003 and it has been constantly updated since then. Currently, the most commonly used BioBricks standard is the assembly standard 10, or BBF RFC 10. BioBricks defines the prefix and suffix sequences required for a DNA part to be compatible with the BioBricks assembly method, allowing the joining of all DNA parts which are in the BioBricks format. The prefix contains the restriction sites for EcoRI, NotI and XBaI, while the suffix contains the SpeI, NotI and PstI restriction sites. Outside of the prefix and suffix regions, the DNA part must not contain these restriction sites. To join two BioBrick parts together, one of the plasmids is digested with EcoRI and SpeI while the second plasmid is digested with EcoRI and XbaI. The two EcoRI overhangs are complementary and will thus anneal together, while SpeI and XbaI also produce complementary overhangs which can also be ligated together. As the resulting plasmid contains the original prefix and suffix sequences, it can be used to join with more BioBricks parts. Because of this property, the BioBricks assembly standard is said to be idempotent in nature. However, there will also be a "scar" sequence (either TACTAG or TACTAGAG) formed between the two fused BioBricks.
Sources: en.wikipedia.org
Vaginal discharge may indicate a vaginal infection by color and odor, or the resulting symptoms of discharge, such as irritation or burning. Abnormal vaginal discharge may be caused by STIs, diabetes, douches, fragranced soaps, bubble baths, birth control pills, yeast infection (commonly as a result of antibiotic use) or another form of vaginitis. While vaginitis is an inflammation of the vagina, and is attributed to infection, hormonal issues, or irritants, vaginismus is an involuntary tightening of the vagina muscles during vaginal penetration that is caused by a conditioned reflex or disease. Vaginal discharge due to yeast infection is usually thick, creamy in color and odorless, while discharge due to bacterial vaginosis is gray-white in color, and discharge due to trichomoniasis is usually a gray color, thin in consistency, and has a fishy odor. Discharge in 25% of the trichomoniasis cases is yellow-green. HIV/AIDS, human papillomavirus (HPV), genital herpes and trichomoniasis are some STIs that may affect the vagina, and health sources recommend safe sex (or barrier method) practices to prevent the transmission of these and other STIs. Safe sex commonly involves the use of condoms, and sometimes female condoms (which give women more control). Both types can help avert pregnancy by preventing semen from coming in contact with the vagina.
== Taxonomy == The name Artocarpus is derived from the Greek words artos ("bread") and karpos ("fruit"). This name was coined by Johann Reinhold Forster and J. Georg Adam Forster, a father-and-son team of botanists aboard HMS Resolution on James Cook's second voyage; they used it in their book Characteres generum plantarum. It is maintained as a conserved name. Although fossils of Artocarpus have been reported from as early as the Late Cretaceous, these fossils generally that lack key diagnostic characters such as that could definitively place them in the genus. The last common ancestor of all living Artocarpus likely originated in the vicinity of Borneo, from which Artocarpus dispersed elsewhere in Asia and Oceania.
== Chemistry == The chemical name is 1-deoxy-1 (methylamino)-D-glucitol, 1-(6-amino-3,5-difluoropyridin-2-yl)-8-chloro-6-fluoro-7-(3-hydroxyazetidin-1-yl)-4-oxo-1,4-dihydroquinoline-3-carboxylate (salt). The injectable form of delafloxacin is sold as the meglumine salt of the active ingredient and its United States Adopted Name, delafloxacin meglumine, reflects that; the injection formulation also includes EDTA and sulfobutylether-β-cyclodextrin. The tablet is made of delafloxacin, citric acid anhydrous, crospovidone, magnesium stearate, microcrystalline cellulose, povidone, sodium bicarbonate, and sodium phosphate monobasic monohydrate.
== Board of directors == The board of directors is composed of thirteen members, in office until the approval of the financial statements at 31 December 2020, with Alberto Vacchi in the role of chairman and executive CEO. Marco Vacchi is the honorary president.
=== Type 1 diabetes === Research has shown that beta cells can be differentiated from human pancreas progenitor cells. These differentiated beta cells, however, often lack much of the structure and markers that beta cells need to perform their necessary functions. Examples of the anomalies that arise from beta cells differentiated from progenitor cells include a failure to react to environments with high glucose concentrations, an inability to produce necessary beta cell markers, and abnormal expression of glucagon along with insulin. In order to successfully re-create functional insulin producing beta cells, studies have shown that manipulating cell-signal pathways in early stem cell development will lead to those stem cells differentiating into viable beta cells. Two key signal pathways have been shown to play a vital role in the differentiation of stem cells into beta cells: the BMP4 pathway and the kinase C. Targeted manipulation of these two pathways has shown that it is possible to induce beta cell differentiation from stem cells. These variations of artificial beta cells have shown greater levels of success in replicating the functionality of natural beta cells, although the replication has not been perfectly re-created yet. Studies have shown that it is possible to regenerate beta cells in vivo in some animal models.
Sources: en.wikipedia.org
== BDNF-AS == The genomic locus encoding BDNF is structurally complex and also encodes BDNF-antisense (BDNF-AS; also known as BDNFOS or ANTI-BDNF). BDNF-AS is a long non-coding RNA (lncRNA) transcribed from the opposite strand of the BDNF gene. This lncRNA was identified in 2005 through searches in expressed sequence tag (EST) databases and subsequent RT-PCR experiments. The gene encoding BDNF-AS is located on chromosome 11p14.1. BDNF mRNA and BDNF-AS share a common overlapping region and form double-stranded RNA (dsRNA) duplexes. BDNF-AS regulates BDNF expression and can suppress BDNF mRNA. In the human neocortex, regions with increased activity and BDNF expression exhibit reduced BDNF-AS expression. Elevated BDNF-AS levels are associated with reduced BDNF expression and have been shown to promote neurotoxicity, increase apoptosis, and decrease cell viability. Conversely, inhibiting BDNF-AS upregulates BDNF mRNA, activates BDNF-mediated signaling pathways, increases BDNF protein levels, suppresses neuronal apoptosis, and promotes neuronal outgrowth and differentiation. The BDNF-AS gene consists of 10 exons and a functional promoter upstream of exon 1. The BDNF-AS gene generates numerous distinct non-coding RNAs through alternative splicing. This diversity of spliced isoforms is a common feature of eukaryotic organisms, particularly in the nervous system. Notably, BDNF-AS is absent in rodents, although highly homologous sequences are present in the genomes of chimpanzees and rhesus monkeys, suggesting a primate/hominid evolutionary origin of BDNF-AS.
=== Venezuela === Early on 3 September, tributes containing photos, videos and names of the deceased began to appear on social media. There was no response from the Maduro administration for four hours after the strike was announced; Freddy Ñáñez, the Venezuelan communications minister, was the first Venezuelan official to address the strike. He stated that the footage of the attack was fake. Inhabitants of San Juan de Unare disagree with this version. During his regular TV show on 3 September, Diosdado Cabello, Venezuela's Minister of Interior, Justice and Peace, characterized the strike as "fake news" "invented" by the US as a cover for regime change. In the TV segment, he called the killings extrajudicial murders. Cabello later said that Venezuelan investigations determined none of the 11 people killed were members of Tren de Aragua. A neighbor of one of the missing people disagreed with this version. The next day, on 4 September, Attorney General Tarek William Saab said the attack never occurred. Maduro accused the US of threatening regime change with the strike and build up of naval forces in the area. He said there were no criminal connections to drug traffickers. Delcy Rodríguez, the vice president of Venezuela, asked on 8 September, "How can there be a drug cartel if there's no drugs here?" In November 2025, Yván Gil, Venezuela's foreign minister, issued a statement saying that "Venezuela categorically, firmly, and absolutely rejects the new and ridiculous fabrication by the Secretary of the U.S.
== Scar free healing in nature == Unlike the limited regeneration seen in adult humans, many animal groups possess an ability to completely regenerate damaged tissue. Full limb regeneration is seen both in invertebrates (e.g. starfish and flatworms which can regenerate fully functioning appendages) and some vertebrates, however in the latter this is almost always confined to the immature members of the species: an example being tadpoles which can regrow their tails and various other body parts, an ability not seen in the mature frogs. The exception to this is the much studied urodele species' of amphibians, also known as salamanders, which carry their ability of complete regeneration into adulthood. These vertebrates possess an exceptional ability to allow regeneration of entire limbs and their tails (as well as a multitude of their internal organs as well, including their spinal cord) through a process known as blastema formation. This involves covering of the wound by a layer of epithelial cells known as the wound cap and subsequent innervation of this area with nerves that give off signals that revert local differentiated cells (such as muscle, cartilage and connective tissue) back to their undifferentiated cell lineage also known as mesenchymal cells. It is this area that is known as the blastema which has the potential to differentiate and proliferate once again allowing regrowth of the limb similar to how it occurs during development.
Forcipulatida (6 families, 63 genera, 269 species) Species in this order have distinctive pedicellariae, consisting of a short stalk with forceps-like tips. and tube feet with flat-tipped suckers usually arranged in four rows. The order includes well-known species from temperate and cold-water regions, ranging from intertidal to abyssal zones. Notomyotida (1 family, 8 genera, 75 species) These starfish are deep-sea dwelling and have particularly flexible arms with distinctive lines of musculature along the sides of the dorsal region. In some species, the tube feet lack suckers.
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.
It is a seven-amino-acid peptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, produced by chemical synthesis rather than extracted from biological tissue. Its design is based on tuftsin, a natural immunomodulatory tetrapeptide. The C-terminal Pro-Gly-Pro segment is a common stabilising motif in short regulatory peptides.