Tuftsin analog 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 2026-01-24. Where a claim depends on a specific study, the study is described rather than over-claimed.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue with a C-terminal Pro-Gly-Pro tail |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Abbreviated TKPRPGP in most catalogues |
| Molecular mass | About 752 Da | Value for the free peptide |
| Solubility | Freely soluble in water | Aqueous solutions are kept cold and used promptly |
| Typical storage | -20 °C, dry, protected from light | Applies to the lyophilised powder before reconstitution |
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
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.
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.
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.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
Historian Jacques Lévesque framed these changes within a pattern he termed "negotiated revolutions," distinguishing the top-down transitions engineered in Poland and Hungary from the popular uprisings that followed in East Germany, Czechoslovakia, and Romania, which for audiences across the bloc, signaled that the Brezhnev Doctrine was truly dead.
Trump, who previously served as the 45th president of the United States from 2017 to 2021 and lost his reelection bid to Joe Biden in the 2020 presidential election, announced his candidacy for the nomination of the Republican Party in the 2024 presidential election on November 15, 2022. In March 2024, Trump secured the Republican nomination. Trump selected Senator JD Vance of Ohio, a former critic of his, as his running mate, and the two were officially nominated at the 2024 Republican National Convention. Early on November 6, 2024, the day after the election, Trump was projected to have secured the presidency. Trump won the presidential election with 312 electoral votes and 49.8% of the popular vote, while Kamala Harris received 226 electoral votes and 48.3% of the popular vote. Trump, upon taking office, became the second president in U.S. history to serve non-consecutive terms after Grover Cleveland in 1893, and the first with a felony to serve the presidency after his conviction in May 2024. In the concurrent congressional elections, Republicans secured a government trifecta after retaining their majority in the House of Representatives and winning back control of the Senate for the first time since his first presidency.
Obsidian tools found in Mission Santa Clara have shown the existence of exchange networks between various tribes in California. Lithic analysis helps to understand pre-Hispanic groups in Mesoamerica. A careful analysis of obsidian in a culture or place can be of considerable use to reconstruct commerce, production, and distribution, and thereby understand economic, social and political aspects of a civilization. For example, the coastal Chumash sites in California indicate considerable trade with the distant site of Casa Diablo Hot Springs in the Sierra Nevada. Obsidian in California comes from five major locations all around the state, and when Mission Santa Clara was built, the tribes took their obsidian tools with them and from the analysis of the obsidian tools it showed that all five major location of obsidian were present. While in Mesoamerica, at the Maya city of Yaxchilán, even warfare implications have been studied linked with obsidian use and its debris. Green Pachuca obsidian was highly prized: it has been argued Teotihuacan monopolized the Pachuca deposit to control and influence Obsidian trade in Central Mexico during the Classic Period, and the Mexica of Tenochtitlan (the capital of the Aztec Empire), favored Pachuca obsidian for ritual deposits after rising to power. A scraper made from Pachuca obsidian has even been found at Spiro Mounds in Oklahoma.
traditional chains are spatially short, involve a small number of local intermediaries, but lack product diversification, quality and safety standards, and economies of scale; transitional supply chains are spatially longer, with many small and medium agrifood enterprises (SMAEs) handling midstream processing and distribution; modern chains, which supply large urban populations mainly with horticultural and animal products, are dominated by multinationals in their midstream and downstream segments. The limited resources available to small-scale producers and small and medium agrifood enterprises (SMAEs) often make recovery following a disruption more difficult. SMAEs tend to be labour-intensive with limited capacity to manage risks associated with product perishability and seasonality. Being heavily interdependent, disruption anywhere in the supply chain can produce a harmful cascading effect. FAO suggests that facilitating access to credit and information can create synergies between efficiency and resilience that accelerate recovery. Governments can also support better coordination and organization of SMAEs within food supply chains. One approach is to form consortia, which increase the scale, visibility and influence of small businesses and facilitate access to private and government funding. Nurturing inter-organizational relationships in networks or strategic alliances can generate relational, structural and cognitive capital, promote more robust and effective risk management through resource pooling, and improve access to modern technologies and know-how.
==== History ==== All Sendai virus strains belong to the same serotype. The origin of many strains of SeV was described in 1978. Some strains such as Ohita and Hamamatsu were described later. Ohita and Hamanatsu strains were isolated from separate epidemics in laboratory mice. According to the personal memory of Alisa G. Bukrinskaya, who has co-authored numerous publications related to SeV along with Viktor M. Zhdanov, starting in 1961, the Moscow strain of SeV was obtained by Viktor M. Zhdanov of the Ivanovsky Institute of Virology from Japan in the late 1950s or early 1960s, It is reported that the BB1 strain derived from the Moscow virus strain. The strain BB1 was given to the researchers of Institute of Viral Disease Control and Prevention, Beijing, China by researchers of Ivanovsky Institute of Virology, Moscow, Russia in the 1960s.
Sources: en.wikipedia.org
==== Wound healing ==== High dose aspirin treatment (which inhibits cyclooxygenases-1 and -2 to block their production of 12-HHT), thromboxane synthase knockout, and BLT2 receptor knockout, but not TXA2 receptor knockout, impair keratinocyte-based re-epithelialization and thereby closure of experimentally induced wounds in mice. A synthetic BLT2 receptor agonist accelerates wound closure not only in this mouse model but also in the db/db mouse model of obesity, diabetes, and dyslipidemia due to leptin receptor deficiency. 12-HHT accumulated in the wounds of the former mouse model. Companion studies using an in vitro scratch test assay indicated that 12-HHT stimulated human and mouse keratinocyte migration by a BLT2 receptor-dependent mechanism that involved the production of tumor necrosis factor α and metalloproteinases. These results indicate that the 12-HHT/BLT2 receptor axis is a critical contributor to wound healing in mice and possibly humans. The axis operates by recruiting the movement of keratinocytes to close the wound. This mechanism may underlie the suppression of wound healing that accompanies the high dose intake of aspirin and, based on mouse studies, other non-steroidal anti-inflammatory agents (NSAIDs) in humans. Synthetic BLT2 agonists may be useful for speeding the healing of chronic ulcerative wounds, particularly in patients with, for example diabetics, that have impaired wound healing.
=== Other types === A further class of alcohol dehydrogenases belongs to quinoenzymes and requires quinoid cofactors (e.g., pyrroloquinoline quinone, PQQ) as enzyme-bound electron acceptors. A typical example for this type of enzyme is methanol dehydrogenase of methylotrophic bacteria.
Tropoelastin is a protein, of size 72kDa, that comes together via cross-links to form elastin in the extracellular matrix of the cell. The cross-link formation process is mediated by lysyl oxidase. One of the major reasons that elastin can withstand high levels of stress in the body without experiencing any physical deformation is that the underlying tropoelastin contains domains that are highly hydrophobic. These hydrophobic domains, consisting overwhelmingly of alanine, proline, glycine, and valine, tend towards instability and disorderliness, ensuring that the elastin does not lock into any specific confirmation. Thus, ELPs consisting of the Val-Pro-Gly-X-Gly monomeric units, which bear resemblance to the repetitive tropoelastin hydrophobic domains, are highly disordered below their Tt. Even above their Tt in their aggregated state, ELPs are only partially ordered. This is due to the fact that the proline and glycine amino acids are present in high amounts in the ELP. Glycine, due to the lack of a bulky side chain, enables the biopolymer to be flexible and proline prevents the formation of stable hydrogen bonds in the ELP backbone. Certain segments of the ELP may be able to form instantaneous type II β turns, but these turns are not long-lasting and do not resemble true β sheets, when the NMR chemical shifts are compared.
Several different types of fluorescent probes, like cyanine dyes, methyl violegen, or semiconductor quantum dots can be conjugated to silica nanoparticles and delivered into specific cells or injected in vivo. Carrier molecule RGD peptide has been very useful of targeted in vivo imaging. Topically applied surface-enhanced resonance Raman ratiometric spectroscopy (TAS3RS)- TAS3RS is another technique that is starting to make advancement in the medical field. It is an imaging technique that uses Folate Receptors (FR) to detect tumor lesions as small as 370 micrometers. Folate Receptors are membrane bound surface proteins that bind folates and folate conjugates with high affinity. FR is frequently overexpressed in a number of human malignancies including cancer of the ovary, lung, kidney, breast, bladder, brain, and endometrium. Raman imaging is a type of spectroscopy that is used in chemistry to provide structural fingerprint by which molecules can be identified. It relies upon inelastic scattering of photons, which result in ultra high sensitivity. There was a study that was done where two different surface enhanced resonance Raman scattering were synthesized (SERRS).
== Detection and monitoring == Detection and monitoring of CEC is done through a variety of sophisticated analytical techniques. High-performance liquid chromatography (HPLC) paired with mass spectrometry (MS) can help identify organic CEC, due to their high sensitivity and selectivity EPA. For volatile and semi-volatile compounds, gas chromatography (GC) coupled with MS is commonly used FDA. Metals and metalloids are typically analyzed using techniques like inductively coupled plasma mass spectrometry (ICP-MS), which allows for the simultaneous analysis of multiple elements USGS. The complications with monitoring CEC go past just detection. Their pathways across different environmental also must be monitored. This can be done with passive sampling devices, which accumulate contaminants over time and give a comprehensive view of contaminant levels at different locations NOAA. Biosensors are also used and integrated to detect specific contaminants rapidly, which is important for on-site monitoring applications NIH. The use of remote sensing and geographic information systems (GIS) for spatial analysis is expanding, these tools facilitate the tracking of pollution spread NASA Earth Science. Recent advancements in nanotechnology have led to the development of nano-sensors which can detect trace amounts of CEC Nature Nanotechnology. There are sites with waste that would take hundreds of years to clean up and prevent further seepage and contamination into the water table and surrounding biosphere.
Sources: en.wikipedia.org
== Mechanism == Three main changes are seen in the mechanism of Raynaud's phenomenon: reduced blood flow, blood vessel constriction, and neurogenic, inflammatory, and immune responses. It is induced by emotional stress and coldness. In all cases, the primary cause is an underlying hyperactivation of the sympathetic nervous system, although the exact pathophysiology differs depending on the type. In the primary type, there is an increase in sensitivity due to the issues mentioned above, resulting in vasoconstriction. In the secondary type, normal activity of blood vessels is disrupted due to the same issues, causing vasoconstriction which leads to ischemia and tissue death.
== Phases == The course of the action potential can be divided into five parts: the rising phase, the peak phase, the falling phase, the undershoot phase, and the refractory period. During the rising phase the membrane potential depolarizes (becomes more positive). The point at which depolarization stops is called the peak phase. At this stage, the membrane potential reaches a maximum. Subsequent to this, there is a falling phase. During this stage the membrane potential becomes more negative, returning towards resting potential. The undershoot, or afterhyperpolarization, phase is the period during which the membrane potential temporarily becomes more negatively charged than when at rest (hyperpolarized). Finally, the time during which a subsequent action potential is impossible or difficult to fire is called the refractory period, which may overlap with the other phases. The course of the action potential is determined by two coupled effects. First, voltage-sensitive ion channels open and close in response to changes in the membrane voltage Vm. This changes the membrane's permeability to those ions. Second, according to the Goldman equation, this change in permeability changes the equilibrium potential Em, and, thus, the membrane voltage Vm. Thus, the membrane potential affects the permeability, which then further affects the membrane potential. This sets up the possibility for positive feedback, which is a key part of the rising phase of the action potential.
Dinosaurs belong to a group known as archosaurs, which also includes modern crocodilians. Within the archosaur group, dinosaurs are differentiated most noticeably by their gait. Dinosaur legs extend directly beneath the body, whereas the legs of lizards and crocodilians sprawl out to either side. Collectively, dinosaurs as a clade are divided into two primary branches, Saurischia and Ornithischia. Saurischia includes those taxa sharing a more recent common ancestor with birds than with Ornithischia, while Ornithischia includes all taxa sharing a more recent common ancestor with Triceratops than with Saurischia. Anatomically, these two groups can be distinguished most noticeably by their pelvic structure. Early saurischians—"lizard-hipped", from the Greek sauros (σαῦρος) meaning "lizard" and ischion (ἰσχίον) meaning "hip joint"—retained the hip structure of their ancestors, with a pubis bone directed cranially, or forward. This basic form was modified by rotating the pubis backward to varying degrees in several groups (Herrerasaurus, therizinosauroids, dromaeosaurids, and birds). Saurischia includes the theropods (exclusively bipedal and with a wide variety of diets) and sauropodomorphs (long-necked herbivores which include advanced, quadrupedal groups). By contrast, ornithischians—"bird-hipped", from the Greek ornis (ὀρνίς) meaning "bird" and ischion (ἰσχίον) meaning "hip joint"—had a pelvis that superficially resembled a bird's pelvis: the pubic bone was oriented caudally (rear-pointing).
Display Stream Compression (DSC) is a VESA-developed video compression algorithm designed to enable increased display resolutions and frame rates over existing physical interfaces, and make devices smaller and lighter, with longer battery life.
=== COVID-19 === Research has been conducted to explore the possibility of developing a heterologous SARS-CoV receptor-binding domain (RBD) recombinant protein as a human vaccine against COVID-19. The theory is supported by evidence that convalescent serum from SARS-CoV patients have the ability to neutralise SARS-CoV-2 (corresponding virus for COVID-19) and that amino acid similarity between SARS-CoV and SARS-CoV-2 spike and RBD protein is high (82%).
Sources: en.wikipedia.org
Selank is a seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.
Tuftsin is a natural tetrapeptide derived from the Fc portion of immunoglobulin G. Selank retains that tetrapeptide at its N-terminus and adds three residues to improve resistance to enzymatic breakdown. The relationship is structural, and the two molecules are not interchangeable in experimental work.
It holds a product registration in Russia for intranasal use as an anxiolytic. Registrations of that kind are not automatically accepted by regulators elsewhere. In most other countries it is treated as an unapproved substance or a research material.
Intranasal administration predominates in both animal and human research because it avoids hepatic first-pass metabolism. Injectable and intraperitoneal routes appear in animal work mainly for comparison.