amino acid sequence is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-03-12. 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.
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.
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.
| 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.
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.
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.
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.
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.
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
{\displaystyle {\begin{aligned}{\frac {dn}{dt}}A\,dx&=\left[J(x+dx)-J(x)\right]{\frac {A}{e}}+(G_{n}-R_{n})A\,dx\\&=\left[J(x)+{\frac {dJ}{dx}}dx-J(x)\right]{\frac {A}{e}}+(G_{n}-R_{n})A\,dx\\[1.2ex]{\frac {dn}{dt}}&={\frac {1}{e}}{\frac {dJ}{dx}}+(G_{n}-R_{n})\end{aligned}}}
The aim of cognition-oriented treatments, which include reality orientation and cognitive retraining, is the reduction of cognitive deficits. Reality orientation consists of the presentation of information about time, place, or person to ease the understanding of the person about his or her surroundings and his or her place in them. On the other hand, cognitive retraining tries to improve impaired capacities by exercising mental abilities. Both have reported some efficacy in improving cognitive capacities. Stimulation-oriented treatments include art, music, and pet therapies, exercise, and any other kind of recreational activities. Stimulation has modest support for improving behavior, mood, and, to a lesser extent, function. Nevertheless, as important as these effects are, the main support for the use of stimulation therapies is the change in the person's routine.
Echocardiography Electroencephalography (EEG) Lumbar puncture Magnetic resonance imaging or computed tomography (CT) scan of the brain (alterations in caudate nucleus and putaminal enlargement have been described in some patients)
== Boxing scandals == List of deaths due to injuries sustained in boxing In 1967, then-undefeated World Champion Muhammad Ali was stripped of his title, and denied a boxing license for the next 3 years over his refusal to be drafted into the U.S. army. In 1983, boxer Luis Resto was caught tampering with his gloves by removing padding and hardening his hand wraps with plaster. In 2001, International Boxing Federation founder Robert W. "Bobby" Lee Sr. was convicted of money laundering and tax evasion, following a three-year long investigation of racketeering and bribery at the organization. Tampered handwraps controversy of 2009 resulting in the suspension of Antonio Margarito Suspension of boxing judges at the 2016 Summer Olympics - see Boxing at the 2016 Summer Olympics#Judging
To import or export, sell or offer for sale, supply—even gratuitously—transport, carry, keep in storage, store, administer, or in any way deliver for consumption any narcotic substance, without authorization or in violation of legal or regulatory provisions. This article rendered these drugs illegal and thus authorized police powers and regulatory bodies to impose sanctions on users and traffickers of illicit drugs. Even before their legal prohibition, narcotic drugs were already shrouded in prejudice—particularly racial prejudice, such as in the case of marijuana, which was nicknamed "Angola weed", because it was mainly used by adherents of Afro-Brazilian religions in their rituals. In 1973, when Brazil acceded to the Convention on Psychotropic Substances, the "war on drugs" shifted its approach; the new drug policies clearly defined the penalties and consequences associated with possessing, purchasing, or selling these substances. It was in the Brazilian state's interest to marginalize and prohibit narcotics, given that during the 1968 student marches against the military dictatorship, drugs had been used as a symbol of resistance against the regime—and, due to the lack of clear penalties, users faced neither prosecution nor punishment.
Sources: en.wikipedia.org
Vascularisation is the physiological process through which blood vessels form in tissues or organs. Neovascularization (neo- + vascular + -ization) specifically refers to the growth of new blood supply in a tissue or organ following an injury, chronic inflammation or metabolic distress. Growth factors that modulate neovascularization include those that affect endothelial cell division and differentiation. These growth factors often act in a paracrine or autocrine fashion; they include fibroblast growth factor, placental growth factor, insulin-like growth factor, hepatocyte growth factor, and platelet-derived endothelial growth factor. It may occur through angiogenesis (the formation of new blood vessels form from pre-existing ones), vasculogenesis (the creation of blood vessels during development, particularly in embryos) or arteriogenesis (where smaller vessels become enlarged into fully functioning arteries).
== Early life == Henriksen was born on May 5, 1940 in Manhattan, New York. His father, James Henriksen, was a Norwegian merchant sailor and boxer, who spent most of his life at sea, while his mother, Margueritte Werner, struggled to find work as a dance instructor, waitress and model. His parents divorced when he was two years old, and his mother struggled to raise him and his half-brother Walter, leading to his spending part of his childhood in foster care. During an interview, Henriksen recounted how, at the age of seven, his mother handed him his birth certificate and said, "You'll always know who you are", then pushed him out of his home. Henriksen did not actually leave home until he was 12, saying he'd "had enough" of his home life, and that he had been physically assaulted by multiple maternal family members: "I got bludgeoned a lot. Different people, relatives. I remember every single face from my childhood. My alcoholic uncles, whoever. I'm not having a pity party here; I'm not Quasimodo. That's just how it was". On another occasion, two of his uncles tried to persuade him to take Methadrine and then take part in a staged car accident for the insurance money. Growing up, Henriksen had a reputation for getting into trouble in the various schools he attended, and even spent time in a children's home. He left school after completing first grade, and was illiterate until the age of 30.
Compressors operate on compressible fluids, typically gases. Pumps operate on fluids, typically liquids, approximated as in-compressible. Compressors are intended to develop a very high pressure rise against a closed system; pumps are designed to develop relatively little pressure against a free-flowing system with minimal back-pressure. Pumps are often used in continuous-flow operation, while many lower-end compressors must have intermittent duty cycles. Compressors usually have a feedback sensor to shut off when they reach a desired pressure; pumps have a fixed design and operate freely across their performance curve as conditions change
== Treatment == The treatment is based on addressing obesity, thus reducing insulin resistance and its undesired effects. Insulin resistance can be treated with metformin and may have a positive impact on reproductive function. Pharmacological treatment by suppression of gonadotropin with estrogen-progesterone oral contraceptives can reduce the hyperandrogenism by decreasing LH (luteinizing hormone) levels. Even their sex hormone binding to globulin increase is also responsible for decreasing body's bio-availability of testosterone. Progestin treatment with desogestrel and norgestimate appears to have fewer androgenic side effects and may be safer to use in persons with abnormal lipid levels or hirsutism. Other proposed treatments include antiandrogenic medications, spironolactone (in combination with oral contraceptives to prevent menstrual cycle irregularities), flutamide, and the 5α-reductase inhibitor finasteride.
==== Yeasts ==== Actin's cytoskeleton is key to the processes of endocytosis, cytokinesis, determination of cell polarity and morphogenesis in yeasts. In addition to relying on actin, these processes involve 20 or 30 associated proteins, which all have a high degree of evolutionary conservation, along with many signalling molecules. Together these elements allow a spatially and temporally modulated assembly that defines a cell's response to both internal and external stimuli. Yeasts contain three main elements that are associated with actin: patches, cables, and rings. Despite not being present for long, these structures are subject to a dynamic equilibrium due to continual polymerization and depolymerization. They possess a number of accessory proteins including ADF/cofilin, which has a molecular weight of 16kDa and is coded for by a single gene, called COF1; Aip1, a cofilin cofactor that promotes the disassembly of microfilaments; Srv2/CAP, a process regulator related to adenylate cyclase proteins; a profilin with a molecular weight of approximately 14 kDa that is related/associated with actin monomers; and twinfilin, a 40 kDa protein involved in the organization of patches.
Sources: en.wikipedia.org
=== Biofilms === Bacteria often attach to surfaces and form dense aggregations called biofilms and larger formations known as microbial mats. These biofilms and mats can range from a few micrometres in thickness to up to half a metre in depth, and may contain multiple species of bacteria, protists and archaea. Bacteria living in biofilms display a complex arrangement of cells and extracellular components, forming secondary structures, such as microcolonies, through which there are networks of channels to enable better diffusion of nutrients. In natural environments, such as soil or the surfaces of plants, the majority of bacteria are bound to surfaces in biofilms. Biofilms are also important in medicine, as these structures are often present during chronic bacterial infections or in infections of implanted medical devices, and bacteria protected within biofilms are much harder to kill than individual isolated bacteria.
Ion chromatography (or ion-exchange chromatography; abbreviated IC or IEC) is a form of chromatography that separates ions and ionizable polar molecules based on their affinity to the ion exchanger. It works on almost any kind of charged molecule—including small inorganic anions, large proteins, small nucleotides, and amino acids. However, ion chromatography must be done in conditions that are one pH unit away from the isoelectric point of a protein. The two types of ion chromatography are anion-exchange and cation-exchange. Cation-exchange chromatography is used when the molecule of interest is positively charged. The molecule is positively charged because the pH for chromatography is less than the pI (also known as pH(I)). In this type of chromatography, the stationary phase is negatively charged and positively charged molecules are loaded to be attracted to it. Anion-exchange chromatography is when the stationary phase is positively charged and negatively charged molecules (meaning that pH for chromatography is greater than the pI) are loaded to be attracted to it. It is often used in protein purification, water analysis, and quality control. The water-soluble and charged molecules such as proteins, amino acids, and peptides bind to moieties which are oppositely charged by forming ionic bonds to the insoluble stationary phase.
=== Antiquity === Ancient Babylonian texts describe symptoms resembling migraine, which were believed to be caused by supernatural forces and were treated using spiritual or religious practices. A description consistent with migraine is contained in the Ebers Papyrus, written around 1500 BCE in ancient Egypt. Trepanation, a surgical procedure involving drilling or scraping an opening into the skull, has been practiced since the Neolithic period, although there is little evidence that it was specifically used to treat headaches or migraine. During the Greco-Roman era, explanations for migraine shifted from supernatural beliefs to the theory of the four humors. Writings from the Hippocratic school of medicine described the visual aura that can precede headache and noted that vomiting could provide partial relief. Headaches were thought to result from an imbalance of these bodily fluids. A description by Aretaeus of Cappadocia classified headaches into cephalalgia, cephalea, and heterocrania, while Galen of Pergamon adapted this latter term to produce "hemicrania", from which the modern word migraine is derived. He proposed that the pain arose from the meninges and blood vessels of the head. The mystical visions described by Hildegard von Bingen as "reflections of the living light", have been interpreted by some scholars as being consistent with the visual aura experienced during migraine attacks.
Ribosomes are minute particles consisting of RNA and associated proteins that function to synthesize proteins. Proteins are needed for many cellular functions, such as repairing damage or directing chemical processes. Ribosomes can be either free, floating within the cytoplasm or attached to the rough endoplasmic reticulum. Their main function is to convert genetic code into an amino acid sequence and to build protein polymers from amino acid monomers. Ribosomes act as catalysts in two extremely important biological processes called peptidyl transfer and peptidyl hydrolysis. In summary, ribosomes have two main functions: Decoding the message, and the formation of peptide bonds. These two functions reside in the ribosomal subunits. Each subunit is made of one or more rRNAs and many r-proteins. The small subunit (30S in bacteria and archaea, 40S in eukaryotes) has the decoding function, whereas the large subunit (50S in bacteria and archaea, 60S in eukaryotes) catalyzes the formation of peptide bonds, referred to as the peptidyl-transferase activity. The bacterial (and archaeal) small subunit contains the 16S rRNA and 21 r-proteins (Escherichia coli), whereas the eukaryotic small subunit contains the 18S rRNA and 32 r-proteins (Saccharomyces cerevisiae, although the numbers vary between species). The bacterial large subunit contains the 5S and 23S rRNAs and 34 r-proteins (E. coli), with the eukaryotic large subunit containing the 5S, 5.8S, and 25S/28S rRNAs and 46 r-proteins (S. cerevisiae; again, the exact numbers vary between species).
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.