peptidase 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 2026-01-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
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 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.
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.
| 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 |
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.
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.
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.
He described in a 2022 viral video a hygiene regime that eschews the use of shampoo, soap, deodorant and toothpaste in favor of simply water. He posted a video to his X.com account in May 2024 that promoted feeding "raw dairy" to infants. The post received over 90,000 views and sparked strong backlash before it was removed the following day. He conducted an interview with United States secretary of health and human services Robert F. Kennedy Jr in the White House in May 2025. In the promotional video, the two men are shown drinking shots of raw milk mixed with glyphosate-free honey. Saladino is known for his opposition to seed oils.
== History == In 1921, Joslin reported the association of diabetes with hypertension and hyperuricaemia. In 1923, Kylin expanded on this triad. In 1947, Vague observed that upper-body obesity predisposed to diabetes, atherosclerosis, gout and calculi. The term metabolic syndrome began appearing in the late 1950s. In 1967, Avogaro, Crepaldi and coworkers described moderately obese people with diabetes, hypercholesterolemia, and marked hypertriglyceridemia that improved on hypocaloric, low-carbohydrate diets. In 1977, Hans Haller used the term for associations of obesity, diabetes mellitus, hyperlipoproteinemia, hyperuricemia, and hepatic steatosis. The same year, Singer used it for associations of obesity, gout, diabetes, and hypertension with hyperlipoproteinemia. In 1977–1978, Gerald B. Phillips proposed a "constellation of abnormalities" (glucose intolerance, hyperinsulinemia, hypercholesterolemia, hypertriglyceridemia, hypertension) and hypothesised sex hormones as a linking factor. The first comprehensive definition of the metabolic syndrome was given in 1981 by the German researchers Markolf Hanefeld and Wolfgang Leonhardt, Dresden, who defined it as a cluster of obesity, hyper- and dyslipoproteinemia, type 2 diabetes, gout, and hypertension, associated with an increased incidence of atherosclerotic vascular disease, fatty liver disease, and gallstones. In 1988, Gerald M. Reaven's Banting lecture proposed insulin resistance as the underlying factor and coined syndrome X.
== Optimal copper levels == Copper deficiency and toxicity can be either of genetic or non-genetic origin. The study of copper's genetic diseases, which are the focus of intense international research activity, has shed insight into how human bodies use copper, and why it is important as an essential micronutrient. The studies have also resulted in successful treatments for genetic copper excess conditions, empowering patients whose lives were once jeopardized. In the US, the average daily intake of copper is about 1 mg, and its bioavailability from the diet is estimated to be 65–70%, with a biological half-life of about 13–33 days. Researchers specializing in the fields of microbiology, toxicology, nutrition, and health risk assessments are working together to define the precise copper levels that are required for essentiality, while avoiding deficient or excess copper intakes. Results from these studies are expected to be used to fine-tune governmental dietary recommendation programs which are designed to help protect public health.
== Waitrose effect == Proximity to a supermarket has been widely reported to be an amenity that can have a significant effect on residential property prices in Britain. Beginning under Andy Hulme and continuing under Mike Songer, the home mortgage unit of Lloyds Bank has published pricing research that examines the premiums commanded by homes in a given neighbourhood against comparables in the same post-code and correlates the difference in price with convenience of access to the various supermarkets. The following table averages information from neighbourhoods across England and Wales, compiled by Lloyds Bank for its 2016 report using supermarket location information from CACI Datalab and house price information from HM Land Registry.
== Structure == hPTH-(1-84) crystallizes as a slightly bent, long, helical dimer. The extended helical conformation of hPTH-(1-84) is the likely bioactive conformation. The N-terminal fragment 1-34 of parathyroid hormone (PTH) has been crystallized and the structure has been refined to 0.9 Å resolution.
Sources: en.wikipedia.org
Currently, very few methods are used to synthesize (S)-dapoxetine. This novel approach consists of only six steps in which three main steps are shown above. The initial reactant is trans-cinnamyl alcohol, which is commercially available. Sharpless asymmetric epoxidation and Mitsunobu reaction have been used to produce expected (S)-dapoxetine. The overall yield is 35%. This method is considered a good choice compared to the known methods due to high yield and easily obtainable reactants.
=== A. tumefaciens === Production of siderophores also exhibited in some plant-infecting bacteria, such as Agrobacterium tumefaciens. The enzyme is controlled by gene cluster agb and the production of 2,3-diDHB dehydrogenase is controlled by the gene agbA. The enzyme AgbA is homologous to the EntA enzyme in E. coli, the same enzyme that produces 2,3-diDHB dehydrogenase.
== Dissolution and successor organisations == In December 1998, Democratic Left in England and Wales was formally dissolved and reconstituted as the New Times Network, which adopted a more inclusive membership policy that welcomed members of the Labour Party and other political organisations. The new body published a monthly magazine, New Times, and worked with the Fabian Society to organise the 'Getting Real' conference in June 1999. The New Times Network was subsequently renamed the New Politics Network in December 1999. In Scotland, the organisation evolved separately into Democratic Left Scotland, which was established in May 1998.
The colour-fast (non-fading) dye was an item of luxury trade, prized by Romans, who used it to colour ceremonial robes. Used as a dye, the colour shifts from blue (peak absorption at 590 nm, which is yellow-orange) to reddish-purple (peak absorption at 520 nm, which is green). It is believed that the intensity of the purple hue improved rather than faded as the dyed cloth aged. Vitruvius mentions the production of Tyrian purple from shellfish. In his History of Animals, Aristotle described the shellfish from which Tyrian purple was obtained and the process of extracting the tissue that produced the dye. Pliny the Elder described the production of Tyrian purple in his Natural History:
== First encounters with poverty and teaching career == As an undergraduate in Glasgow, he explored the interior of the city, usually at weekends. He was shocked by what he found in the poverty-stricken slums and tenements, which then made up a large part of the city. Rickets was obvious among the children, malnutrition (in some cases, associated with drunkenness) was shown by many of the adults, and many of the aged were destitute. In his first teaching job after graduating MA in 1902, he was posted to a school in the slums. His first class was overcrowded and the children ill-fed or actually hungry, inadequately clothed, infested with lice and physically wretched. He resigned after a few days since he realised that he could not teach children in such a condition and that there was nothing he could do to relieve their misery. After working for a few months in his father's business, he taught for three years at Kyleshill School in Saltcoats, also a poor area, but less squalid than the slums of Glasgow. Boyd Orr needed to augment his teacher's salary, and decided to do so by instructing an evening class in book-keeping and accountancy. After intensive study he passed the necessary examinations, and duly instructed his class. The knowledge and skills he learned by studying for and teaching this class were to prove useful in his later career.
Sources: en.wikipedia.org
=== Constitutional reform === In 1988, new amendments to the Yugoslav Constitution were adopted, initiating a process of democratization. During 1988 and 1989, a successful round of coups in the Communist party leadership, known as the anti-bureaucratic revolution, in Vojvodina, Kosovo as well as Montenegro, replaced autonomous leaderships in this regions. The coups were led by Slobodan Milošević; supporter of Serbian nationalism. The events were condemned by the communist governments of the western Yugoslav republics (especially SR Slovenia and SR Croatia), who successfully resisted the attempts to expand the revolt onto their territories, and turned against Milošević. The rising antagonism eventually resulted in the dissolution of the ruling League of Communists of Yugoslavia in 1990, and subsequently in the breakup of Yugoslavia. In 1989, Slobodan Milošević was elected as President of the State Presidency of Serbia. He demanded that the federal Yugoslav government act for the interests of Serbia in Kosovo by sending in the Yugoslav People's Army to suppress separatism in the province. At the same time, several reforms of federal electoral system were proposed, with Serbia supporting a "one-citizen, one-vote" system, which would have given a majority of votes to Serbs. By that time, ethnic tensions in Yugoslavia increased, and the ruling League of Communists of Yugoslavia collapsed, followed by the crisis of federal institutions.
=== Photodetector devices === Quantum dot photodetectors (QDPs) can be fabricated either via solution-processing, or from conventional single-crystalline semiconductors. Conventional single-crystalline semiconductor QDPs are precluded from integration with flexible organic electronics due to the incompatibility of their growth conditions with the process windows required by organic semiconductors. On the other hand, solution-processed QDPs can be readily integrated with an almost infinite variety of substrates, and also postprocessed atop other integrated circuits. Such colloidal QDPs have potential applications in visible- and infrared-light cameras, machine vision, industrial inspection, spectroscopy, and fluorescent biomedical imaging.
T-independent type I antigen — Mitogens that induce nonspecific activation of B cells (at smaller doses, they initially appeared specific to particular B cells, suggesting erroneously that this was an antigen-specific process; subsequent investigation proved their nonspecific nature) T-independent type II antigen — Antigens containing multiple repetitive motifs that allow them to crosslink B cell receptors and directly activate the B cells. Bacterial capsule polysaccharides are a common example. Immunodominant antigens – Antigens that dominate (over all others from a pathogen) in their ability to produce an immune response. T cell responses typically are directed against a relatively few immunodominant epitopes, although in some cases (e.g., infection with the malaria pathogen Plasmodium spp.) it is dispersed over a relatively large number of parasite antigens. These are contrasted with immunosubdominant (sometimes referred to just as "subdominant") antigens. Antigen-presenting cells present antigens in the form of peptides on major histocompatibility complexes. All nucleated cells (i.e., all cells except for red blood cells) express MHC class I, which samples peptides from the cytosol, defaulting to presenting self-antigen (unless something foreign ends up in the cytosol or if the cell is capable of cross-presentation). Antigens originating from outside the cell make their way into the endomembrane system via processes like phagocytosis, endocytosis, or macropinocytosis and are loaded onto MHC class II molecules.
=== Art history === In European pre-historic societies, sculptures of female figures with pronounced or highly exaggerated breasts were common. A typical example is the so-called Venus of Willendorf, one of many Paleolithic Venus figurines with ample hips and bosom. Artifacts such as bowls, rock carvings and sacred statues with breasts have been recorded from 15,000 BC up to late antiquity all across Europe, North Africa and the Middle East. Many female deities representing love and fertility were associated with breasts and breast milk. Figures of the Phoenician goddess Astarte were represented as pillars studded with breasts. Isis, an Egyptian goddess who represented, among many other things, ideal motherhood, was often portrayed as suckling pharaohs, thereby confirming their divine status as rulers. Even certain male deities representing regeneration and fertility were occasionally depicted with breast-like appendices, such as the river god Hapy who was considered to be responsible for the annual overflowing of the Nile.
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.
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.