A practical reference on Tuftsin: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-07-23. Anything still debated is marked as such rather than presented as settled.
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 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.
| 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 |
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, with mass spectrometry used to confirm molecular mass and sequence information. Amino acid analysis and peptide mapping may supplement these methods. Certified reference standards are scarce, and many commercial lots are sold as research chemicals without a pharmacopoeial monograph. Regulatory treatment differs by country: Selank is a registered prescription medicine in Russia, while in the European Union and the United States it is not an approved drug and may fall under research-chemical or unapproved-product frameworks.
Selank is a hydrophilic peptide and dissolves readily in water and in aqueous buffers. The lyophilised powder is typically a white to off-white solid. Because short peptides are prone to hydrolysis and oxidation, handling benefits from limiting exposure to heat, moisture and strong light. Working solutions are commonly prepared in sterile water or saline, and repeated freeze-thaw cycles are avoided to reduce aggregation and loss of activity. These practices reflect general laboratory convention rather than published stability specifications.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
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.
=== Ribosomes make proteins === In the 1950s, results of labeling experiments in rat liver showed that radioactive amino acids were found to be associated with "microsomes" (later redefined as ribosomes) very rapidly after administration, and before they became widely incorporated into cellular proteins. Ribosomes were first visualized using electron microscopy, and their ribonucleoprotein components were identified by biophysical methods, chiefly sedimentation analysis within ultracentrifuges capable of generating very high accelerations (equivalent to hundreds of thousands times gravity). Polysomes (multiple ribosomes moving along a single mRNA molecule) were identified in the early 1960s, and their study led to an understanding of how ribosomes read the mRNA in a 5′ to 3′ direction, generating proteins as they do so.
== Function == CHS catalysis serves as the initial step for flavonoid biosynthesis. Flavonoids are important plant secondary metabolites that serve various functions in higher plants. These include pigmentation, UV protection, fertility, antifungal defense and the recruitment of nitrogen-fixing bacteria. CHS is believed to act as a central hub for the enzymes involved in the flavonoid pathway. Studies have shown that these enzymes interact via protein-protein interactions. Through FLIM FRET, it was shown that CHS interacts with chalcone isomerase (CHI), a consecutive step enzyme, as well as other non-consecutive step enzymes flavanone 3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), and flavonol synthase I. Naringenin-chalcone synthase uses malonyl-CoA and 4-coumaroyl-CoA to produce CoA, naringenin chalcone, and CO2.
The sans-culottes (French: [sɑ̃kylɔt]; lit. 'without breeches') were the common people of the lower classes in late 18th-century France, a great many of whom became radical and militant partisans of the French Revolution in response to their poor quality of life under the Ancien Régime. The name sans-culottes refers to their clothing, and through that to their lower-class status: culottes were the fashionable silk knee-breeches of the 18th-century nobility and bourgeoisie, and the working class sans-culottes wore pantaloons, or long trousers, instead. The sans-culottes, most of them urban labourers, served as the driving popular force behind the revolution. The word sans-culotte, which is opposed to "aristocrat", seems to have been used for the first time on 28 February 1791 by Jean-Bernard Gauthier de Murnan in a derogatory sense, speaking about a "sans-culottes army". The word came into vogue during the demonstration of 20 June 1792. They were judged by the other revolutionaries as "radicals" because they advocated a direct democracy, that is to say, without intermediaries such as members of parliament. Though ill-clad and ill-equipped, with little or no support from the middle and upper classes, they made up the bulk of the Revolutionary army and were responsible for many executions during the early years of the French Revolutionary Wars. According to Peter Stephen Du Ponceau, secretary and interpreter to Baron de Steuben, Steuben first used the expression sans culottes in 1778: "The Baron loved to speak of that dinner, and of his sans culottes as he called us.
== See also == All pages with titles containing Link Linc (disambiguation) Lincs (disambiguation) Linker (disambiguation) Linq (disambiguation) Linx (disambiguation) Lynx (disambiguation) Microsoft Lync Linkt, road tolling brand in Australia
=== Secretion of Interleukin-10 === Genetically engineered L. lactis can secrete the cytokine interleukin-10 (IL-10) for the treatment of inflammatory bowel diseases (IBD), since IL-10 has a central role in downregulating inflammatory cascades and matrix metalloproteinases. A study by Lothar Steidler and Wolfgang Hans shows that in situ synthesis of IL-10 by genetically engineered L. lactis requires much lower doses than systemic treatments like antibodies to tumor necrosis factor (TNF) or recombinant IL-10. The authors propose two possible routes by which IL-10 can reach its therapeutic target. Genetically engineered L. lactis may produce murine IL-10 in the lumen, and the protein may diffuse to responsive cells in the epithelium or the lamina propria. Another route involves L. lactis being taken up by M cells because of its bacterial size and shape, and the major part of the effect may be due to recombinant IL-10 production in situ in intestinal lymphoid tissue. Both routes may involve paracellular transport mechanisms that are enhanced in inflammation. After transport, IL-10 may directly downregulate inflammation. In principle, this method may be useful for intestinal delivery of other protein therapeutics that are unstable or difficult to produce in large quantities and an alternative to the systemic treatment of IBD.
Sources: en.wikipedia.org
== Cannabinoids == Cannabinoids are the compounds found in cannabis, which is a euphoriant and hallucinogenic drug prepared from the dried leaves of the strong-smelling plant Cannabis sativa. It includes synthetic cannabinoids (spice, K2), and tetrahydrocannabinol (THC, Delta-8).
Although limited in their authority, these assemblies represented a move in the direction of representative government at the national level, and by 1880 assemblies also had been formed in villages and towns. In 1880 delegates from twenty-four prefectures held a national convention to establish the Kokkai Kisei Dōmei. Although the government was not opposed to parliamentary rule, confronted with the drive for "people's rights", it continued to try to control the political situation. New laws in 1875 prohibited press criticism of the government or discussion of national laws. The Public Assembly Law (1880) severely limited public gatherings by disallowing attendance by civil servants and requiring police permission for all meetings. Within the ruling circle, however, and despite the conservative approach of the leadership, Okuma continued as a lone advocate of British-style government, a government with political parties and a cabinet organized by the majority party, answerable to the national assembly. He called for elections to be held by 1882 and for a national assembly to be convened by 1883; in doing so, he precipitated a political crisis that ended with an 1881 imperial rescript declaring the establishment of a national assembly in 1890 and dismissing Okuma. Rejecting the British model, Iwakura and other conservatives borrowed heavily from the Prussian constitutional system. One of the Meiji oligarchy, Itō Hirobumi (1841–1909), a Chōshū native long involved in government affairs, was charged with drafting Japan's constitution.
The embryo undergoes well-characterized morphogenetic movements during gastrulation and early development, including germ-band extension, formation of several furrows, ventral invagination of the mesoderm, and posterior and anterior invagination of endoderm (gut), as well as extensive body segmentation until finally hatching from the surrounding cuticle into a first-instar larva. During larval development, tissues known as imaginal discs grow inside the larva. Imaginal discs develop to form most structures of the adult body, such as the head, legs, wings, thorax, and genitalia. Cells of the imaginal disks are set aside during embryogenesis and continue to grow and divide during the larval stages—unlike most other cells of the larva, which have differentiated to perform specialized functions and grow without further cell division. At metamorphosis, the larva forms a pupa, inside which the larval tissues are reabsorbed and the imaginal tissues undergo extensive morphogenetic movements to form adult structures.
Cytosine is a nucleotide that is present in both DNA and RNA. However, uracil is only found in RNA. Therefore, after UTP is synthesized, it must be converted into a deoxy form to be incorporated into DNA. This conversion involves the enzyme ribonucleoside triphosphate reductase. This reaction that removes the 2'-OH of the ribose sugar to generate deoxyribose is not affected by the bases attached to the sugar. This non-specificity allows ribonucleoside triphosphate reductase to convert all nucleotide triphosphates to deoxyribonucleotide by a similar mechanism. In contrast to uracil, thymine bases are found mostly in DNA, not RNA. Cells do not normally contain thymine bases that are linked to ribose sugars in RNA, thus indicating that cells only synthesize deoxyribose-linked thymine. The enzyme thymidylate synthetase is responsible for synthesizing thymine residues from dUMP to dTMP. This reaction transfers a methyl group onto the uracil base of dUMP to generate dTMP. The thymidylate synthase reaction, dUMP + 5,10-methylenetetrahydrofolate ⇔ dTMP + dihydrofolate, is shown to the right.
=== Economic issues === Sanders focuses on economic issues such as income and wealth inequality, poverty, raising the minimum wage, universal healthcare, canceling all student debt, making public colleges and universities tuition-free by taxing financial transactions, establishing a 32-hour work week, and expanding Social Security benefits by eliminating the cap on the payroll tax on incomes above $250,000. He has become a prominent supporter of laws requiring companies to give their workers parental leave, sick leave, and vacation time, noting that nearly all other developed countries have such laws. He also supports legislation that would make it easier for workers to join or form a trade union. He opposed the Troubled Asset Relief Program and has called for comprehensive financial reforms, such as breaking up "too big to fail" financial institutions, restoring Glass–Steagall legislation, reforming the Federal Reserve Bank, and allowing the Post Office to offer basic financial services in economically marginalized communities. Believing greater emphasis is needed on labor rights and environmental concerns when negotiating international trade agreements, Sanders voted against and has long spoken against NAFTA, CAFTA, and PNTR with China. He has called them a "disaster for the American worker", saying that they have resulted in American corporations moving abroad.
Sources: en.wikipedia.org
Polymer-protein hybrids are a class of nanostructure composed of protein-polymer conjugates (i.e. complexes composed of one protein attached to one or more polymer chains). The protein component generally gives the advantages of biocompatibility and biodegradability, as many proteins are produced naturally by the body and are therefore well tolerated and metabolized. Although proteins are used as targeted therapy drugs, the main limitations—the lack of stability and insufficient circulation times still remain. Therefore, protein-polymer conjugates have been investigated to further enhance pharmacologic behavior and stability. By adjusting the chemical structure of the protein-polymer conjugates, polymer-protein particles with unique structures and functions, such as stimulus responsiveness, enrichment in specific tissue types, and enzyme activity, can be synthesized. Polymer-protein particles have been the focus of much research recently because they possess potential uses including bioseparations, imaging, biosensing, gene and drug delivery.
Research mainly focuses on polymers that show thermoresponsivity in aqueous solution. Promising areas of application are tissue engineering, liquid chromatography, drug delivery and bioseparation. Only a few commercial applications exist, for example, cell culture plates coated with an LCST-polymer.
EDTA forms such strong complexes with most divalent cations that it finds many uses. For example, it is often present in washing powder to act as a water softener by sequestering calcium and magnesium ions. The selectivity of macrocyclic ligands can be used as a basis for the construction of an ion selective electrode. For example, potassium selective electrodes are available that make use of the naturally occurring macrocyclic antibiotic valinomycin.
== Discovery == Studies conducted in the 1970s found that a series of N-formylmethionine-containing oligopeptides, including the most potent and best known member of this series, N-formylmethionine-leucyl-phenylalanine (fMLF or fMet-Leu-Phe), stimulated rabbit and human neutrophils by an apparent receptor-dependent mechanism to migrate in a directional pattern in classical laboratory assays of chemotaxis. Since these oligopeptides were produced by bacteria or synthetic analogs of such products, it was suggested that the N-formyl oligopeptides are important chemotactic factors and their receptors are important chemotactic factor receptors that act respectively as signaling and signal-recognizing elements to initiate inflammation responses in order to defend against bacterial invasion. Further studies defined a receptor for the N-formyl oligopeptides, formyl peptide receptor (FPR), so named based on its ability to bind and become activated by the oligopeptides. Two receptors where thereafter discovered and named FPR1 and FPR2 based on the similarity of their genes' predicted amino acid sequence to that of FPR rather than on any ability to bind or be activated by the formyl oligopeptides.
== Mechanism of action == The exact mechanism of action of silicone gel sheeting has not been fully studied. Currently, many proposed mechanisms explain the efficacy of such treatment, including the occlusion and hydration effect, increased body surface temperature, polarized electric charge, immunological effects, etc. The occlusion and hydration effect is the most studied mechanism of action.
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.
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.