The short version of tuftsin fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-03-12 and is reviewed periodically as new material appears.
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.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity report | 95% or higher by HPLC | Area percentage at 214 nm |
| Identity confirmation | Mass spectrometry | Electrospray or MALDI |
| Powder storage | -20 C, desiccated | Protect from light |
| Solution storage | 2-8 C short term | Freeze aliquots for longer |
| Quality document | Certificate of analysis | States method and value |
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
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.
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.
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
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.
=== May 2005 === A Pentagon order is mentioned in a military report filed on May 16, 2005 ordering U.S. personnel to turn a blind eye to Iraqi torture by refraining from investigating instances of apparent detainee abuse by Iraqi personnel, unless the investigation is first approved by U.S. headquarters: "Provided the initial report confirms US forces were not involved in the detainee abuse, no further investigation will be conducted unless directed by HHQ." Such approval was rarely granted.
== Diagnosis == The history of a preceding influenza-like infection followed by the typical symptoms of acute onset of symmetrical calf pain and gait problems together with an isolated finding of a high level of creatine kinase suggests the diagnosis of BACM. Myoglobinuria is rare and points to the possibility of the development of rhabdomyolysis and kidney failure. Guillain-Barré syndrome (GBS) is the main consideration in the differential diagnosis. It needs to be quickly excluded as early intervention in GBS is indicated. Other conditions under possible consideration are dermatomyositis, muscular dystrophy, juvenile idiopathic arthritis, transient synovitis of the hip, osteomyelitis, and myalgia. Few muscle biopsies have been conducted. Results may show normal findings or features of inflammation and necrosis.
=== Setting === Opposing Force is set in the same location and timeframe as that of Half-Life, taking place at a remote New Mexico laboratory called the Black Mesa Research Facility. In Half-Life, the player takes on the role of Gordon Freeman, a scientist involved in an accident that opens an interdimensional portal to the borderworld of Xen, allowing the alien creatures of Xen to attack the facility. The player controls Freeman in an attempt to escape the facility and close the portal, ultimately traveling to Xen to do so. Opposing Force, however, shows the events of Half-Life from the perspective of a different protagonist. The player assumes the role of Adrian Shephard, a U.S. Marine Corps Corporal assigned to the Hazardous Environment Combat Unit, a specialized unit sent in to Black Mesa by the government to quell the alien threat and silence all witnesses. However, after Shephard becomes isolated from his fellow Marines, he must ally with the Black Mesa personnel and attempt to escape the base.
Sources: en.wikipedia.org
In 2004, Gaddafi traveled to the headquarters of the European Union (EU) in Brussels—signifying improved relations between Libya and the EU—and the EU dropped its sanctions on Libya. As a strategic player in Europe's attempts to stem illegal migration from Africa, in October 2010, the EU paid Libya over €50 million to stop African migrants passing into Europe; Gaddafi encouraged the move, saying that it was necessary to prevent the loss of European cultural identity to a new "Black Europe". Gaddafi also completed agreements with the Italian government that they would invest in various infrastructure projects as reparations for past Italian colonial policies in Libya. Italian Prime Minister Silvio Berlusconi gave Libya an official apology in 2006, after which Gaddafi called him the "iron man" for his courage in doing so. In August 2008, Gaddafi and Berlusconi signed a historic cooperation treaty in Benghazi; under its terms, Italy would pay $5 billion to Libya as compensation for its former military occupation. In exchange, Libya would take measures to combat illegal immigration coming from its shores and boost investment in Italian companies. After the US removed Libya from its list of state sponsors of terrorism in 2006, Gaddafi nevertheless continued his anti-Western rhetoric. At the 2008 Arab League summit, held in Syria, he warned fellow Arab leaders that they could be overthrown and executed by the US like Saddam Hussein.
=== Protists === A common protist eukaryotic expression system is the slime mold, Dictyostelium discoideum, and is unique as it has a circular plasmid, packaged similarly to chromatin. As a simple eukaryotic haploid organism, it can grow in high concentrations without the expensive conditions of mammalian cell culture, and perform post-translational modifications. The protein itself is expressed in several forms including as membrane attached, secreted, or cell associated, and can glycosylate protein product.
James Wallace Jorgenson is an American academic who previously held the position of William Rand Kenan Jr. Distinguished Professor of Chemistry at UNC-Chapel Hill. He is best known for his work developing capillary zone electrophoresis, and is a member of the American Academy of Arts and Sciences.
== Nomenclature == All enzymes including radical SAM enzymes follow an easy guideline for systematic naming. Systematic naming of enzymes allows a uniform naming process that is recognized by all scientists to understand corresponding function. The first word of the enzyme name often shows the substrate of the enzyme. The position of the reaction on the substrate will also be in the beginning portion of the name. Lastly, the class of the enzyme will be described in the other half of the name which will end in suffix -ase. The class of an enzyme will describe what the enzyme is doing or changing on the substrate. For example, a ligase combines two molecules to form a new bond.
Sources: en.wikipedia.org
Komagataella kurtzmanii G.I.Naumov, E.S.Naumova, Tyurin & Kozlov, 2013 Komagataella mondaviorum G.I.Naumov, E.S.Naumova & K.L.Boundy-Mills, 2018 Komagataella pastoris (Guillierm., 1919) Y.Yamada, M.Matsuda, K.Maeda & Mikata, 1995 Komagataella phaffii Kurtzman, 2005 – responsible for most, if not all, industrial & research use Komagataella populi Kurtzman, 2012 Komagataella pseudopastoris (Dlauchy, Tornai-Leh., Fülöp & G.Péter, 2003) Kurtzman, 2005 Komagataella ulmi Kurtzman, 2012
=== Nonketotic hyperosmolar syndrome === Nonketotic hyperosmolar syndrome (also known as hyperglycemic hyperosmolar syndrome) is a rare but extremely serious complication of untreated canine diabetes, which is a medical emergency. It shares the symptoms of extreme hyperglycemia, dehydration, and lethargy with ketoacidosis; because there is some insulin in the system, the body does not begin to turn to using fat as its energy source and there is no ketone production. There is not sufficient insulin available to the body for proper uptake of glucose, but there is enough to prevent ketone formation. The problem of dehydration in NHS is more profound than in diabetic ketoacidosis. Seizures and coma are possible. Treatment is similar to that of ketoacidosis, with the exceptions being that NHS requires that the blood glucose levels and rehydration be normalized at a slower rate than for DKA; cerebral edema is possible if the treatment progresses too rapidly.
The two substrates of this enzyme are L-DOPA and oxygen. Its initial product is 4-(L-alanin-3-yl)-2-hydroxy-cis,cis-muconate 6-semialdehyde. The intermediate readily cyclises and further oxidises, forming a 2-pyrone ring; this stizolobic acid, which is the product that is isolated and after which this enzyme is named.
Sources: en.wikipedia.org
Purity is usually reported as an HPLC area percentage, most often measured at 214 nm. Identity is confirmed separately by mass spectrometry. A certificate of analysis should state both the method and the observed value.
Dry powder is kept frozen, desiccated, and shielded from light. Dissolved material is aliquoted and frozen to limit freeze-thaw cycles. Short-term refrigerated storage is common for working solutions.
Russia registers it as a prescription nasal product. Most other markets classify it as a research chemical with no approved medical use. Oversight of purity and labeling is consequently minimal in those markets.
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.