Enkephalinase 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.
Last reviewed on 2026-02-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Free peptide form |
| Molecular mass | About 751.9 Da | Calculated average mass |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form TKPRPGP |
| Structural basis | Tuftsin analogue | Extended version of a natural tetrapeptide |
| Development origin | Russian Academy of Sciences | Work carried out from the 1980s onward |
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.
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.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
Despite the independence of strain rate, preconditioned soft tissues still present hysteresis, so the mechanical response can be modeled as hyperelastic with different material constants at loading and unloading. By this method the elasticity theory is used to model an inelastic material. Fung has called this model as pseudoelastic to point out that the material is not truly elastic.
In contrast with EOD, the incidence of LOD has remained unchanged at 0.24-0.26 per 1000 live births in the US. S. agalactiae neonatal meningitis does not present with the hallmark sign of adult meningitis, a stiff neck; rather, it presents with nonspecific symptoms, such as fever, vomiting, and irritability, and can consequently lead to a late diagnosis.
Moscow Mayor Sergei Sobyanin announced that the newly opened Moscow-based "R-Pharm" will become a leading manufacturer of Russia's Sputnik V coronavirus vaccine. Working at full capacity, the factory will produce up to 10 million doses a month. In May 2021 Sergei Sobyanin complained that only 1.3 million Moscow residents out of 12 million had received the first dose (10.2%). Only 9.5% of Russians had received a vaccine. Forbes Russia established that Russia committed to export 205 millions of doses of "Sputnik V" to other countries, and as of 16 May.3 millions (8%) were so far delivered. A survey found that 62% of the Russian population felt hesitant, with 55% not afraid of getting sick and some willing to wait for CoviVac. In June 2021, with the increase in Delta variant cases, several Russian city governments introduced strict measures to overcome vaccine hesitancy, such as requiring vaccine QR codes from customers in cafes.
shall, until the contrary is proved, be presumed to have had that drug in his possession. Furthermore, any person who has a controlled drug in his possession shall be presumed to have known the nature of that drug. The majority of executions in Singapore are for drug offences. Since 2010, 23 prisoners have been executed for drug offences, while only five have been executed for other offences, such as murder. Death penalty supporters, such as blogger Benjamin Chang, claim that Singapore has one of the lowest prevalence of drug abuse worldwide. Chang claims, for instance, that over two decades, the number of drug abusers arrested each year has declined by two-thirds, from over 6,000 in the early 1990s to about 2,000 in 2011. The validity of these figures is disputed by other Singaporeans, such as drugs counsellor Tony Tan. The United Nations Office on Drugs and Crime notes that Singapore remains a transit destination for drug traffickers in Asia, drug seizures continue to increase, and heroin drug use within Singapore is continuing to rise. Ironically, Singapore's reputation for having some of the toughest anti drug laws in the world has in the past made it an attractive transit point for drug traffickers, as foreign airport officials knew the vast majority of people would not risk the death penalty for carrying drugs via the city state.
== Mechanotaxis in development == Cell migration is essential in early embryonic development, as a defining characteristic of this phase is the folding and reorganization of the embryo that occurs during and after gastrulation. Without cell migration, complex structures involving multiple cell types that make up complex organisms – like tissues, organs, limbs, etc. – would not develop correctly. There are multiple factors that influence cells to move during development –– but the factors that influence mechanotaxis in development often involve interactions between cells or between a cell and a substrate such as a yolk or membrane. Contact inhibition of locomotion is involved in the migration of many cell types, including neural crest (NC) cells in vertebrates which give rise to cells of the peripheral nervous system (PNS), facial cartilage, and other non-neural cells throughout the body. NC cells are very mobile, with actin-rich protrusions at the leading edge of each cell in the direction of travel. When an NC cell collides with another NC cell, activation of the Wnt planar cell polarity (PCP) signaling pathway occurs at the point of cell contact, causing localized activation of the downstream effector RhoA. This activation is likely caused by interactions between cadherins on the cell surfaces, and leads to the retraction of the cell protrusions and a change in the cell's polarity, causing the NC cell to change direction.
Sources: en.wikipedia.org
== Prevention of water contamination == Human water-borne diseases usually come from other humans, thus human-derived materials (feces, medical waste, wash water, lawn chemicals, gasoline engines, garbage, etc.) should be kept far away from water sources. For example, human excreta should be buried well away (>60 meters/200 feet) from water sources to reduce contamination. In some wilderness areas it is recommended that all waste be packed up and carted out to a properly designated disposal point.
=== Advocacy and guidelines === Kalra has been the lead or senior author of several national and regional guidelines on obesity and nutrition. He has published several papers highlighting the need for advocacy to address the obesity epidemic in India, including issues of gender disparity. He has also advocated strategies to prevent obesity in the Indian population. Advocacy efforts beyond India include publications highlighting regional challenges and the need for greater collaboration among South Asian countries. He is also a co-author of expert recommendations on the pre-operative and post-operative medical management of patients undergoing bariatric surgery.
Though a good signal may be achieved through glycerol or glycerol with an additive, there could be other matrix compounds that can offer an even better signal. Optimization of matrix compounds and concentration of solid analyte are vital for FAB measurements.
== Community metabolism == The common ancestor of the now existing cellular lineages (eukaryotes, bacteria, and archaea) may have been a community of organisms that readily exchanged components and genes. It would have contained:
Sources: en.wikipedia.org
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.
The core four residues correspond to tuftsin, which occurs naturally as part of immunoglobulin G. The full seven-residue sequence, however, is not a known endogenous peptide. It is a laboratory-designed analogue intended to combine tuftsin-like activity with greater resistance to breakdown.
No single receptor has been confirmed as the primary target. Reports describe involvement of the GABAergic system, interference with enkephalin degradation, and shifts in neurotrophic factor expression. Because these observations come from different models and assays, they have not yet been integrated into one accepted mechanism.
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.