tuftsin raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-05-20 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Stabilized analog of tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Monoisotopic mass about 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in common polar solvents |
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.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
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.
New drugs are the products of a long drug development process, the first step of which is often the discovery of a new enzyme inhibitor. There are two principle approaches of discovering these inhibitors. The first general method is rational drug design based on mimicking the transition state of the chemical reaction catalysed by the enzyme. The designed inhibitor often closely resembles the substrate, except that the portion of the substrate that undergoes chemical reaction is replaced by a chemically stable functional group that resembles the transition state. Since the enzyme has evolved to stabilise the transition state, transition state analogues generally possess higher affinity for the enzyme compared to the substrate, and therefore are effective inhibitors. The second way of discovering new enzyme inhibitors is high-throughput screening of large libraries of structurally diverse compounds to identify hit molecules that bind to the enzyme. This method has been extended to include virtual screening of databases of diverse molecules using computers, which are then followed by experimental confirmation of binding of the virtual screening hits. Complementary approaches that can provide new starting points for inhibitors include fragment-based lead discovery and DNA Encoded Chemical Libraries (DEL). Hits from any of the above approaches can be optimised to high affinity binders that efficiently inhibit the enzyme.
The valley is home to a great variety of wildlife including deer, foxes, and the occasional coyote, while the river hosts salmon and catfish. The Rouge River Valley forms a part of Rouge National Urban Park, a national urban park situated along the eastern portion of Scarborough, and its neighbouring municipalities. Along the shore of Lake Ontario is the earthen escarpment formation known as the Scarborough Bluffs. The Bluffs are about 14 kilometres (8.7 mi) long, and reach heights of more than 60 metres (200 ft) in places. They are part of a much larger formation known as the Iroquois Shoreline, most of which is located somewhat further inland. The Iroquois Shoreline marks the extent of a prehistoric lake, Glacial Lake Iroquois, whose level was quite a bit higher than present-day Lake Ontario's. It shrank in size at the close of the last ice age. Erosion has been a problem along the Scarborough Bluffs. Properties located near the brink have been abandoned, and houses condemned, as the brink wears back away from the lake. Since the 1980s, large areas of beach at the base of the Bluffs have been reinforced with limestone breakwaters and construction rubble infilling.
March 19: Law facilitating donations to public or private charitable organizations, particularly those focused on increasing birth rates and protecting children and war orphans. April 23: Decree implementing the law of April 23, 1919, establishing an eight-hour workday in hotels, restaurants, cafés, and other food service establishments in the Paris region. May 9: Decree modifying the statutes of the Comédie-Française: both principal and substitute members must include at least one woman in each group. June 1: Circular regulating prostitution among women. July 25: Decree on the regulation of films; women may sit on the commission that grants film distribution visas. August 9: Competitive exams for editorial and translator-editor positions in the central administration of commerce and industry are opened to women for a provisional period of three years. August 27: Competitive exams for editorial and calculation clerk positions in the central administration of the Ministry of Labor and Social Welfare are opened to female candidates. October 24: Law protecting breastfeeding women: needy mothers breastfeeding their infants receive special allowances during the first year. October 25: Law creating and organizing chambers of agriculture in each French department; women with agricultural professions (or who had such work during the war) may vote and be elected. 1920
Sources: en.wikipedia.org
Key functions of the USSR were highly centralized in Moscow until its final years, despite its nominal structure as a federation of republics; the light decentralization reforms during the era of perestroika (restructuring) and glasnost (openness) conducted by Mikhail Gorbachev as part of the Helsinki Accords are cited as one of the factors which led to the dissolution of the USSR in 1991 as a result of the Cold War and the creation of the Commonwealth of Independent States. The Karelo-Finnish Soviet Socialist Republic, a relic of the Soviet-Finnish War (the Winter War), became the only union republic to be deprived of its status in 1956. The decision to downgrade Karelia to an autonomous republic within the Russian SFSR was made unilaterally by the central government without consulting its population. The official basis for downgrading the status of the republic was the changes that had occurred in the national composition of its population (about 80% of the inhabitants were Russians, Belarusians and Ukrainians), as well as the need to reduce the state apparatus, the cost of maintaining which in 1955 amounted to 19.6 million rubles.
== Prognosis == G6PD-deficient individuals do not appear to acquire any illnesses more frequently than other people, and may have less risk than other people for acquiring ischemic heart disease and cerebrovascular disease. However, a recent study revealed that G6PD deficiency increases cardiovascular risk by up to 70%. The risk conferred by G6PD deficiency is moderate compared with the impact of primary cardiovascular risk factors. Besides, a published review hypothesized that G6PD deficiency could reduce the antiplatelet efficacy of clopidogrel (clopidogrel resistance).
== Dynamic features == β-pleated sheet structures are made from extended β-strand polypeptide chains, with strands linked to their neighbours by hydrogen bonds. Due to this extended backbone conformation, β-sheets resist stretching. β-sheets in proteins may carry out low-frequency accordion-like motion as observed by the Raman spectroscopy and analyzed with the quasi-continuum model.
Sources: en.wikipedia.org
=== Concerns about the medical evidence === Much of the medical evidence presented at trial has been criticised by experts across several specialties, including neonatology, pathology, nursing, biochemistry and forensic toxicology. Points of scrutiny have included the prosecution's assertions that the infants were clinically stable before their collapses, that alternative explanations could be excluded, and that the alleged mechanisms of harm were medically plausible. Controversy has also arisen from the fact that the original post‑mortem reports for the infants—most of whom underwent autopsy—did not identify suspicious or unnatural causes of death. In February 2025, a panel organised and instructed by Letby's defence team that was led by neonatologist Shoo Lee released findings from their own review of the deaths and collapses (see: § Expert panel investigation). The panel claimed that all of the incidents could be explained by natural causes, substandard care, or a combination of both, and claimed no evidence of deliberate harm.
Some antidepressants function partly as selective alpha-2 blockers, but the best-known drug in that class is yohimbine, which is extracted from the bark of the African yohimbe tree. Yohimbine acts as a male potency enhancer, but its usefulness for that purpose is limited by serious side-effects including anxiety and insomnia. Overdoses can cause a dangerous increase in blood pressure. Yohimbine is banned in many countries, but in the United States, because it is extracted from a plant rather than chemically synthesized, it is sold over the counter as a nutritional supplement.
==== New Zealand ==== Sildenafil was reclassified in New Zealand in 2014 so it could be bought over the counter from a pharmacist. It is thought that this reduced sales over the Internet and was safer as males could be referred for medical advice if appropriate.
=== Estonian === Sünnipäevanädalalõpupeopärastlõunaväsimatus meaning "afternoon untiredness of a weekend birthday party" which is 43 letters. 31 lettered word of uusaastaöövastuvõtuhommikuidüll [uːsɑːstaøːvastuvɤtuhomikuidyl] meaning "morning idyll after the new year". There is also the 25 letter long word of põllumajandusministeerium which is "Ministry of Agriculture". The word kuulilennuteetunneliluuk meaning "the hatch a bullet flies out of when exiting a tunnel" is 24 letters long and a palindrome. It could be one of the longest palindromes.
Sources: en.wikipedia.org
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.
It was developed in Russia, at the Institute of Molecular Genetics of the Russian Academy of Sciences, during the 1990s. Most published research originates from Russian institutions. Independent international replication remains limited.
Tuftsin is a natural tetrapeptide with the sequence Thr-Lys-Pro-Arg that participates in immune signaling. Selank extends that sequence with Pro-Gly-Pro at the C-terminus. The added residues are linked to greater resistance to enzymatic breakdown.
Reports describe modulation of GABA signalling, changes in monoamine turnover and effects on neurotrophic factor expression. These observations come mainly from animal and cell studies. A single unifying mechanism has not been demonstrated.