proteolysis 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 2026-03-18. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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, 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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Derived from the seven-residue sequence |
| Molecular weight | About 751.9 g/mol | Average mass; the monoisotopic value is slightly lower |
| Residue count | Seven amino acids | Thr-Lys-Pro-Arg-Pro-Gly-Pro |
| Parent compound | Tuftsin (Thr-Lys-Pro-Arg) | Selank extends tuftsin at the C-terminus |
| Compound class | Synthetic short peptide | Studied in a research setting; not a licensed drug in most markets |
Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.
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.
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.
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
Identity and purity of selank are established with reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The peptide elutes from C18 columns with acetonitrile gradients in water containing trifluoroacetic acid or formic acid, and detection is usually performed by ultraviolet absorbance near 214 nm. Electrospray ionization in positive mode gives a doubly protonated ion near m/z 377, consistent with a mass of about 752 Da. Amino acid analysis or tandem mass spectrometry of fragment ions confirms the sequence. Because the molecule has no aromatic residues, it lacks a usable 280 nm chromophore, so low-wavelength detection or mass spectrometry is required.
Peptide bonds in selank are susceptible to hydrolysis under strongly acidic or basic conditions, and the terminal proline residues are vulnerable to exopeptidase activity in biological samples. Lyophilized powder stored dry at -20 °C typically remains stable for extended periods, whereas aqueous solutions degrade faster and may lose measurable purity within days to weeks depending on pH, temperature, and microbial load. Repeated freeze-thaw cycles promote aggregation and adsorption to container surfaces. For analytical work, solutions are usually prepared fresh, kept cold, and used within a single working day.
Handling follows standard practice for research peptides. Material is weighed in a low-humidity environment because the powder absorbs atmospheric moisture. Purity is reported as the percentage area of the main peak in a chromatogram, with specifications commonly set at 95 percent or higher; values below that threshold indicate the presence of truncated or modified species. Residual trifluoroacetate from purification is often present and may affect mass balance. Certificates of analysis should state the analytical method, the column and gradient used, and the lot-specific retention time so that results can be compared across suppliers.
Genealogy was another ethnic marker. While it was likely that Israelite identity was not exclusively based on blood descent, the Israelites used genealogical self-definition to engage in cultural narcissism, though also in self-representation of impropriety and guilt, as shown in the story of their occasionally morally challenging ancestor, Jacob, a man of blessing and promise but also one who "suffers for his triumphs and pays a price for taking the name 'Israel'". This ambiguous characterization foreshadows "the complexities of the Jewish soul". Names were significant in Israelite culture and indicated one's destiny and inherent character. Thus, a name change indicated a 'divine transformation' in one's 'destines, characters and natures'. These beliefs aligned with the Near Eastern cultural milieu, where names were 'intimately bound up with the very essence of being and inextricably intertwined with personality'. In terms of appearance, rabbis described the Biblical Jews as being "midway between black and white" and having the "color of the boxwood tree". Assuming Yurco's debated claim that the Israelites are depicted in reliefs from Merneptah's temple at Karnak is correct, the early Israelites may have wore the same attire and hairstyles as non-Israelite Canaanites. Dissenting from this, Anson Rainey argued that the Israelites in the reliefs looked more similar to the Shasu. Based on biblical literature, it is implied that the Israelites distinguished themselves from peoples like the Babylonians and Egyptians by not having long beards and chin tufts.
== Side effects == Neumega has caused allergic reaction which at times have been very serious. Symptoms have been edema of the face and tongue, or larynx; shortness of breath; wheezing; chest pain; hypotension (including shock); dysarthria; loss of consciousness, rash, urticaria, flushing, and fever. These reaction can occur after the first dose or after any later application. Neumega should be permanently discontinued in patients with any sign of allergy. Treatment is largely symptomatic. Oprelvekin also has caused quite often fluid retention, ranging from peripheral edema (approximately 40% of patients) to dyspnea and full developed lung edema with or without cardiac decompensation (see contraindications and precautions). These symptoms have led to some deaths. Fluid retention may also lead to dilutional anemia (in 10 to 15% of patients). Hypokalemia may also result. Symptoms of fluid retention have been observed more often in patients following myeloablative chemotherapy (see contraindications). Severe arrhythmias (atrial flutter and atrial fibrillation) as well as fatal cardiac arrest have also been seen which may or may be not attributed to fluid retention/increased volume. Isolated cases of stroke have been noted, those patients with previous transient ischemic attacks or partial/minor strokes may be at particular risk. Papilledema of the eyes has been observed (2%) and may lead to disturbed visual acuity and even temporary or permanent blindness. Patients with preexisting papilledema or with involvement of the central nervous system may be at higher risk.
Pharmacy informatics is the combination of pharmacy practice science and applied information science. Pharmacy informaticists work in many practice areas of pharmacy, however, they may also work in information technology departments or for healthcare information technology vendor companies. As a practice area and specialist domain, pharmacy informatics is growing quickly to meet the needs of major national and international patient information projects and health system interoperability goals. Pharmacists in this area are trained to participate in medication management system development, deployment, and optimization.
Sources: en.wikipedia.org
A number of Neanderthal fossils had been discovered before their antiquity was fully understood. The first Neanderthal remains—Engis 2 (a skull)—were discovered in 1829 by Dutch/Belgian prehistorian Philippe-Charles Schmerling in the Grottes d'Engis, Belgium. He concluded that these "poorly developed" human remains must have been buried at the same time and by the same causes as the co-existing remains of extinct animal species. In 1848, Gibraltar 1 from Forbes' Quarry was presented to the Gibraltar Scientific Society by their Secretary Lieutenant Edmund Henry Réné Flint, but was thought to be a modern human skull. In 1856, local schoolteacher Johann Carl Fuhlrott recognised bones from Kleine Feldhofer Grotte in Neander Valley—Neanderthal 1—as distinct from modern humans, and gave them to German anthropologist Hermann Schaaffhausen to study in 1857. It comprised the cranium, thigh bones, right arm, left humerus and ulna, left ilium (hip bone), part of the right shoulder blade, and pieces of the ribs.
Ginkgos have a conical crown in youth which becomes progressively broader and more irregular with age. They are large trees, normally reaching a height of 20–35 m (66–115 ft), with some specimens in China being over 40 m (130 ft). The tree has an angular crown and long, somewhat erratic branches, and is usually deep-rooted and resistant to wind and snow damage. Young trees are often tall and slender, and sparsely branched; the crown becomes broader as the tree ages. A combination of resistance to disease, insect-resistant wood, and the ability to form aerial roots and sprouts makes ginkgos durable, with some specimens estimated to be more than 3,500 years old.
=== Type 2 Diabetes === Failure in the regulation of glyceroneogenesis may lead to type 2 diabetes, a metabolic disorder that results in high levels of blood glucose and blood lipid. Type 2 diabetes, in addition to a decreased sensitivity to insulin, is associated with the overproduction of triglycerides in the liver, due to excessively active glyceroneogenesis and excess release of fatty acids from adipose tissues. Glyceroneogenesis can be regulated by controlling the gene expression of PEPC-K. Overexpressing PEPC-K in the liver will overproduce triglycerides and elevate the lipid level in the bloodstream, increasing the risk of fatty liver disease (hepatic steatosis). Conversely, in adipose tissue, down-regulated glyceroneogenesis may decrease de novo lipogenesis, increasing the export of free fatty acids to the bloodstream, leading to lipodystrophy. Both of these conditions are highly associated with type 2 diabetes.
The Stuart Patton Auditorium in the Agricultural Sciences and Industries Building at Penn State is dedicated in his honor “for his inquisitive nature and skill in imparting knowledge; for his enthusiasm for science and uncompromising respect for peers.” In 2018, Dr. Patton's colleague, Ian H. Mather, added this touching tribute to Patton in his article in the Journal of Dairy Science: "This review is dedicated to the memory of Stuart Patton (1920–2017), Evan Pugh Professor Emeritus, Pennsylvania State University, and colleague, friend, and unofficial mentor of the senior author (IHM). The footprints of Dr. Patton’s research are evident throughout the pages of this review" (article is Symposium Review: Intravital imaging of the lactating mammary gland in live mice reveals novel aspects of milk-lipid secretion In a letter submitted in support of Patton's nomination as a fellow of the American Dairy Science Association in 2001, Dr. Ian Maher stated the following, "Dr. Patton's research is characterized by careful attention to experimental detail and a thorough knowledge of the literature. The discussion sections of his papers are always brimming with ideas, thought provoking and creative. A consistent feature of the work is novelty, whether it is a simple solution to a practical problem, or an inspirational idea that leads to new avenues of research. An example of the former is the simple but elegant method Dr. Patton devised to separate milk-fat globules from skim-milk components in a single step by density gradient centrifugation (Patton, S., and Huston, G.E.
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.
Tuftsin contains four residues, while selank carries an additional Pro-Gly-Pro segment at the carboxyl end. That extension is intended to reduce enzymatic cleavage. Comparative pharmacokinetic data in humans remain limited.
No single receptor target is widely accepted as the definitive mediator of the reported effects. Proposed contributors include GABAergic modulation, shifts in monoamine turnover, and altered neuropeptide degradation. The mechanism is treated in the literature as unresolved.
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.