This is a working overview of GABA-A modulation, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-02-22 and is reviewed periodically as new material appears.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analog of the tetrapeptide tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Reported consistently across pharmacopoeial descriptions |
| Appearance | White to off-white lyophilized powder | Typical form of research-grade material |
| Solubility | Freely soluble in water | Aqueous buffers; poor in nonpolar solvents |
| Typical storage temperature | -20 degrees Celsius | Lyophilized powder; protect from moisture |
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.
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.
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.
The term dog has been used as a synonym for sausage since the 1800s, possibly from accusations that sausage makers used dog meat in their sausages. In Germany the consumption of dog meat was common in Saxony, Silesia, Anhalt, and Bavaria during the 19th and 20th centuries. Hot dogs occasionally contained it. An early use of the term hot dog in reference to the sausage-meat appears in 1884:
The substrates of this enzyme are glutathione and cystine. Its products are glutathione disulfide and cysteine. This enzyme belongs to the family of oxidoreductases, specifically those acting on a sulfur group of donors with a disulfide as acceptor. The systematic name of this enzyme class is glutathione:cystine oxidoreductase. Other names in common use include GSH-cystine transhydrogenase, and NADPH-dependent GSH-cystine transhydrogenase. This enzyme participates in cysteine metabolism and glutathione metabolism.
5-HT2C receptor agonists are a class of drugs that activate 5-HT2C receptors. They have been investigated for the treatment of a number of conditions including obesity, psychiatric disorders, sexual dysfunction and urinary incontinence. The 5-HT2C receptors are one of three subtypes that belong to the serotonin 5-HT2 receptor subfamily along with 5-HT2A and 5-HT2B receptors. The development of 5-HT2C agonists has been a major obstacle, because of severe side effects due to a lack of selectivity. Activation of 5-HT2A receptors can induce hallucinations, and the activation of 5-HT2B receptors has been implicated in cardiac valvular insufficiency and possibly in pulmonary hypertension.
Sources: en.wikipedia.org
Another application of CE in forensics is ink analysis, where the analysis of inkjet printing inks is becoming more necessary due to increasingly frequent counterfeiting of documents printed by inkjet printers. The chemical composition of inks provides very important information in cases of fraudulent documents and counterfeit banknotes. Micellar electrophoretic capillary chromatography (MECC) has been developed and applied to the analysis of inks extracted from paper. Due to its high resolving power relative to inks containing several chemically similar substances, differences between inks from the same manufacturer can also be distinguished. This makes it suitable for evaluating the origin of documents based on the chemical composition of inks. It is worth noting that because of the possible compatibility of the same cartridge with different printer models, the differentiation of inks on the basis of their MECC electrophoretic profiles is a more reliable method for the determination of the ink cartridge of origin (its producer and cartridge number) rather than the printer model of origin. A specialized type of CE, affinity capillary electrophoresis (ACE), utilizes intermolecular binding interactions to understand protein-ligand interactions. Pharmaceutical companies use ACE for a multitude of reasons, with one of the main ones being the association/binding constants for drugs and ligands or drugs and certain vehicle systems like micelles. It is a widely used technique because of its simplicity, rapid results, and low analyte usage.
== Genetic transformation == Of the 59 species listed in the table with their clinical characteristics, 11 species (or 19%) are known to be capable of natural genetic transformation. Natural transformation is a bacterial adaptation for transferring DNA from one cell to another. This process includes the uptake of exogenous DNA from a donor cell by a recipient cell and its incorporation into the recipient cell's genome by recombination. Transformation appears to be an adaptation for repairing damage in the recipient cell's DNA. Among pathogenic bacteria, transformation capability likely serves as an adaptation that facilitates survival and infectivity. The pathogenic bacteria able to carry out natural genetic transformation (of those listed in the table) are Campylobacter jejuni, Enterococcus faecalis, Haemophilus influenzae, Helicobacter pylori, Klebsiella pneumoniae, Legionella pneumophila, Neisseria gonorrhoeae, Neisseria meningitidis, Staphylococcus aureus, Streptococcus pneumoniae and Vibrio cholerae.
{\displaystyle \int \limits _{\Omega }\rho {\dfrac {\partial \mathbf {u} }{\partial t}}\cdot \mathbf {v} +\int \limits _{\Omega }\mu \nabla \mathbf {u} \cdot \nabla \mathbf {v} +\int \limits _{\Omega }\rho (\mathbf {u} \cdot \nabla )\mathbf {u} \cdot \mathbf {v} -\int \limits _{\Omega }p\nabla \cdot \mathbf {v} =\int \limits _{\Omega }\mathbf {f} \cdot \mathbf {v} +\int \limits _{\partial \Omega }\left(\mu {\frac {\partial \mathbf {u} }{\partial {\hat {\mathbf {n} }}}}-p{\hat {\mathbf {n} }}\right)\cdot \mathbf {v} \quad \forall \mathbf {v} \in V.}
There are many challenges surrounding human remains accessioned by museums, including legal complications involved in dealing with human remains, involvement of living relatives or tribes, and potential repatriation and issues such as the Native American Graves Protection and Repatriation Act of 1990 (NAGPRA). NAGPRA requires any federal or federally-funded institution, with the exception of the Smithsonian Institution, to submit full inventories of their Native American funerary and sacred objects and human remains and to repatriate these objects to their tribe of origin should a request be made to do so. Should a museum possess human remains which have a direct living relative or group (Native American or otherwise), it is their ethical obligation to involve these individuals in the care and treatment of the remains. Acquisition of human remains by museums can happen in a number of ways, some of which are considered to be unethical today. Many museums have human remains in their collections which have been there for over a hundred years, in which case they may likely have been acquired in ethically or morally unsound ways. This has led to growing concerns that the display of human remains has become depersonalised, by continuing to keep them in collections. Most institutions and museum associations have their own policies on the acquisition of human remains. Some guidelines for the care of human remains including acceptable means of acquisition can be found below.
Sources: en.wikipedia.org
Selank is a synthetic seven-amino-acid peptide modeled on tuftsin, a fragment of the immunoglobulin G heavy chain. It was designed in Russia to combine anxiolytic and immunomodulatory properties in one molecule.
The first four residues of Selank reproduce the tuftsin sequence Thr-Lys-Pro-Arg. A Pro-Gly-Pro extension at the C-terminus was added to slow enzymatic breakdown and extend residence time.
It holds marketing authorization in Russia, where nasal drop formulations are sold. No equivalent approval exists in the European Union, the United States, or most other countries.
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.