Tuftsin analogue raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-12-20. Anything still debated is marked as such rather than presented as settled.
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.
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.
Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Calculated for the free peptide |
| Molecular weight | About 751.9 g/mol | Derived from the sequence |
| Appearance | White to off-white powder | Typical lyophilised form |
Lyophilized Selank, the dry powder form, is generally stored frozen at minus 20 degrees Celsius or colder for long-term keeping. The solid is hygroscopic and should stay sealed, dry, and protected from light. Once dissolved, the peptide is less stable and is usually held refrigerated at 2 to 8 degrees Celsius for short periods. Repeated freezing and thawing is avoided because it can promote aggregation and loss of activity. Buffers and pH choice also affect how long a solution remains usable.
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
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.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
== History == In 1939, Martin Kamen and Samuel Ruben of the Radiation Laboratory at Berkeley began experiments to determine if any of the elements common in organic matter had isotopes with half-lives long enough to be of value in biomedical research. They synthesized 14C using the laboratory's cyclotron accelerator and soon discovered that the atom's half-life was far longer than had been previously thought. This was followed by a prediction by Serge A. Korff, then employed at the Franklin Institute in Philadelphia, that the interaction of thermal neutrons with 14N in the upper atmosphere would create 14C. It had previously been thought that 14C would be more likely to be created by deuterons interacting with 13C. At some time during World War II, Willard Libby, who was then at Berkeley, learned of Korff's research and conceived the idea that it might be possible to use radiocarbon for dating.
=== PPAR-alpha agonists === An endogenous compound, 7(S)-Hydroxydocosahexaenoic Acid (7(S)-HDHA), which is a docosanoid derivative of the omega-3 fatty acid DHA was isolated as an endogenous high affinity ligand for PPAR-alpha in the rat and mouse brain. The 7(S) enantiomer bound with micromolar affity to PPAR alpha with 10 fold higher affinity compared to the (R) enantiomer and could trigger dendritic activation. PPARα (alpha) is the main target of fibrate drugs, a class of amphipathic carboxylic acids (clofibrate, gemfibrozil, ciprofibrate, bezafibrate, pemafibrate and fenofibrate). They were originally indicated for dyslipidemia of cholesterol and more recently for disorders characterized by high triglycerides.
== External links == Eukaryotic Linear Motif resource motif class TRG_NLS_Bipartite_1 Eukaryotic Linear Motif resource motif class TRG_NLS_MonoCore_2 Eukaryotic Linear Motif resource motif class TRG_NLS_MonoExtC_3 Eukaryotic Linear Motif resource motif class TRG_NLS_MonoExtC_4
Sources: en.wikipedia.org
In a TV interview in February 2001, Bush's new attorney general, John Ashcroft, said about the war on drugs, "I want to renew it. I want to refresh it, relaunch it if you will." In 2001, after 9/11 and the Patriot Act, the DEA began highlighting the tie between drug trafficking and international terrorism, gaining the agency expanded funding to increase its global presence.
Solid-state diffusion is the net movement of atoms in solid phase, from a region of higher concentration to one of lower concentration. It is easy to imagine diffusion in a liquid phase as ink spreading in water. Solid-state diffusion of Pb is the net exchange of Pb in the solid mineral with the external environment, which is usually a fluid. In most of the cases, Pb is transported from the mineral to the fluid, resulting in Pb loss and thus age resetting. The rate of diffusion increases with temperature as atoms are moving faster. However, as the mineral cools and the crystal structure becomes more complete, the diffusions of parent and daughter isotopes slow down and finally become insignificant at a certain temperature. This closure temperature (Tc) depends on the crystal size, shape, cooling rate and diffusion coefficient, which in turn varies for each mineral and radioactive systems. That is, above Tc, Pb is continuously lost and the radioactive clock is keeping zero. Once the temperature falls below Tc, the system is closed and the clock starts counting. Monazite is characterized by its high Pb retention ability even at high temperatures for a prolonged period. The closure temperature of monazite in U-Th-Pb system is higher than 800 °C, much higher than the other common minerals.
Animosity between the Allies of World War II predated the end of the war. The death of Franklin D. Roosevelt in April 1945 and the changeover to Harry Truman's presidential administration led to changes in US-Soviet relations as Truman and his staff began to take a harder diplomatic line. US and Soviet diplomats disputed conflicting interpretations of agreements made between Stalin and Roosevelt at the Yalta Conference. Truman's administration was divided on the question of the Polish government's composition, with Truman and several cabinet members advocating for stronger demands that broader democratic elements be included in its ranks. A 1944 accord between Churchill and Stalin further complicated matters in Eastern Europe; the two had agreed to non-interference in one another's spheres of influence, in Greece and in Romania and Bulgaria respectively. The creation of the United Nations in the spring of 1945 led to further disagreements over how the postwar international order should be governed. Because of the alignment of many Latin American nations with the United States, the Soviets feared that a pro-American majority would be used against them. They opposed the admission of Argentina into the UN, and called for a more expansive Security Council veto. Stalin ultimately accommodated the American positions on the UN veto and on the Polish government, allowing Oskar Lange and Stanisław Mikołajczyk to join it.
==== Overdose prevention centers ==== Despite the illegality of injecting illicit drugs in most places around the world, many injectable drug users a report willingness to utilize overdose prevention centers. Those at especially high risk for overdose were significantly more willing. This observed willingness suggests that safe injection sites would be best utilized by people who could benefit most from them. As of 2018, legislation in the US did not allow for the opening of overdose prevention centers; there were no government-sponsored sites but several efforts were underway to try to create them. Critics of overdose prevention centers say they enable and exacerbate drug use. Data from 2014 suggested that safe injection sites could reduce overdoses while not increasing the number of drug users.
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, commonly written as TKPRPGP. It shares the first four residues with tuftsin and carries three prolines in the chain. The proline-rich tail is the main structural feature that separates it from the parent tetrapeptide.
Selank is a synthetic analogue built on the tuftsin tetrapeptide Thr-Lys-Pro-Arg. Extra proline residues were added to the C-terminus during design work. That modification is intended to make the peptide less vulnerable to rapid enzymatic degradation.
Transliteration from Russian produces variant spellings such as Selanc. Many suppliers avoid the trade-style name entirely and list the peptide sequence. Comparing sequences rather than names is the reliable way to confirm two entries describe the same molecule.
Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.