The short version of Pro-Gly-Pro fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-11-06 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised solid form |
| Solubility class | Freely soluble in water | Hydrophilic heptapeptide |
| Dry storage temperature | -20 degrees Celsius or lower | Sealed, desiccated, protected from light |
| Solution storage | 2 to 8 degrees Celsius short term | Avoid repeated freeze-thaw cycles |
| Common identification method | Reversed-phase HPLC with mass spectrometry | Confirms purity and molecular mass |
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
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.
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.
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.
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.
1993/1359) Fresh Meat and Poultry Meat (Hygiene, Inspection and Examinations for Residues) (Charges) (Amendment) Regulations 1993 (S.I. 1993/1360) Pneumoconiosis, Byssinosis and Miscellaneous Diseases Benefit (Amendment) Scheme 1993 (S.I. 1993/1363) Combined Probation Areas (Devon) Order 1993 (S.I. 1993/1364) Barnet, Camden and Westminster (London Borough Boundaries) Order 1993 (S.I. 1993/1365) Crop Residues (Burning) Regulations 1993 (S.I. 1993/1366) Local Government Superannuation (Local Commissioners) Regulations 1993 (S.I. 1993/1367) National Health Service (Fund-Holding Practices) (Scotland) Amendment Regulations 1993 (S.I. 1993/1369) Lancashire County Council (Proposed Connecting Roads to M6 Motorway at Haighton) Special Roads Scheme 1992 Confirmation Instrument 1993 (S.I. 1993/1370) A17 Trunk Road (Leadenham Bypass) Order 1993 (S.I. 1993/1371) A17 Trunk Road (Leadenham Bypass) (Detrunking) Order 1993 (S.I. 1993/1372) King's Lynn—Newark Trunk Road (Leadenham By-pass and Slip Roads) Order 1973 (Revocation) Order 1993 (S.I. 1993/1373) Registered Restrictive Trading Agreements (Inspection, Copy and Certification) (Fees) Regulations 1993 (S.I. 1993/1376) Greater London and Surrey (County and London Borough Boundaries) (No.4) Order 1993 (S.I. 1993/1391)
=== Fermentation medium === The microbes or eukaryotic cells used for fermentation grow in (or on) specially designed growth medium which supplies the nutrients required by the organisms or cells. A variety of media exist, but invariably contain a carbon source, a nitrogen source, water, salts, and micronutrients. In the production of wine, the medium is grape must. In the production of bio-ethanol, the medium may consist mostly of whatever inexpensive carbon source is available. Carbon sources are typically sugars or other carbohydrates, although in the case of substrate transformations (such as the production of vinegar) the carbon source may be an alcohol or something else altogether. For large scale fermentations, such as those used for the production of ethanol, inexpensive sources of carbohydrates, such as molasses, corn steep liquor, sugar cane juice, or sugar beet juice are used to minimize costs. More sensitive fermentations may instead use purified glucose, sucrose, glycerol or other sugars, which reduces variation and helps ensure the purity of the final product. Organisms meant to produce enzymes such as beta galactosidase, invertase or other amylases may be fed starch to select for organisms that express the enzymes in large quantity. Fixed nitrogen sources are required for most organisms to synthesize proteins, nucleic acids and other cellular components. Depending on the enzyme capabilities of the organism, nitrogen may be provided as bulk protein, such as soy meal; as pre-digested polypeptides, such as peptone or tryptone; or as ammonia or nitrate salts.
== Military == The Armed Forces of Serbia and Montenegro (Serbian: Војска Србије и Црне Горе/Vojska Srbije i Crne Gore, ВСЦГ/VSCG), previously known as Army of Yugoslavia (Serbian: Војска Југославије/Vojska Jugoslavije, ВЈ/VJ) included ground forces with internal and border troops, naval forces, air and air defense forces, and civil defense. It was established from the remnants of the Yugoslav People's Army (JNA), the military of the SFR Yugoslavia. Several Bosnian Serb units of the VJ were transferred over to the Republika Srpska, during the course of the Bosnian War, leaving only units directly from Serbia and Montenegro in the armed forces. The VJ saw military action during the Yugoslav Wars, including the Siege of Dubrovnik, as well as the Kosovo War, and played combat roles during ethnic insurgencies. Following the Kosovo War, the VJ was forced to evacuate Kosovo, and in 2003 it was renamed the ''Armed Forces of Serbia and Montenegro.'' Following the dissolution of the Union between Serbia and Montenegro, units from each army were assigned to the independent republics of Serbia and Montenegro, as recruitment in the army was on a local, rather than Federal, level. Montenegro inherited the small navy of the FR Yugoslavia, due to Serbia being landlocked.
The method, known as the Kolbe-Schmitt reaction, entails nucleophilic attack of the phenoxide on carbon dioxide. In some cases, alkenes undergo hydrocarboxylation using a mixture of carbon dioxide and H2:
Sources: en.wikipedia.org
Pictures, movies and applets showing the anatomy of Mus musculus, from www.digimorph.org Michael Purdy: "Researchers add mice to list of creatures that sing in the presence of mates" Archived 2008-12-26 at the Wayback Machine-Study of male mouse "song" with mouse song recording (MP3), by Washington University Medical School "It's just in mice! This scientist is calling out hype in science reporting". STAT. 2019-04-15. Arkive Photographs.Short text. High-Resolution Brain Maps and Brain Atlases of Mus musculus Further reading
The two substrates of this enzyme are geraniol and oxidised nicotinamide adenine dinucleotide phosphate (NADP+). Its products are geranial, reduced NADPH, and a proton. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is geraniol:NADP+ oxidoreductase.
"Dude, people just don't want to eat pink slime". MarketWatch. Retrieved April 4, 2012. Greene, Joel L. (April 6, 2012). "Lean Finely Textured Beef: The 'Pink Slime' Controversy". Congressional Research Service. Retrieved March 2016. Gruley, Bryan; Campbell, Elizabeth (April 12, 2012). "'Pink Slime' Furor Means Disaster For U.S. Meat Innovator". Bloomberg. Retrieved July 19, 2012. Glen, Barb (June 22, 2012). "Lessons learned for Cargill in pink slime's 'ick' factor". The Western Producer. Retrieved July 18, 2012. "Pink slime saga boosts beef exports". The Australian. June 19, 2012. Retrieved July 18, 2012. Wessler, Brett (June 25, 2012). "Former BPI employee plans lawsuit for pink slime frenzy". Drovers/CattleNetwork Magazine. Archived from the original on May 1, 2013. Retrieved July 18, 2012. Siefer, Ted (July 10, 2012). "School board votes to donate 'pink slime'". New Hampshire Union Leader. Archived from the original on June 17, 2013. Retrieved July 18, 2012. Stebbins, Christine (July 12, 2012). "Cargill buys AFA Foods Fort Worth beef processing plant". Reuters. Retrieved October 10, 2013. Engber, Daniel (October 25, 2012). "The Sliming". Slate. Retrieved March 25, 2016. Russell, Joyce (June 19, 2014). "'Pink Slime' Is Making A Comeback. Do You Have A Beef With That?". NPR. Retrieved March 24, 2016. Isidore, Chris (August 13, 2014). "'Pink slime' is back and headed for your burger". CNN Money. Archived from the original on August 16, 2014. Retrieved March 25, 2016. Sanburn, Josh (August 26, 2014). "'Pink Slime' Ground Meat is Back". Time. Retrieved March 24, 2016.
=== Pharmacokinetics === Oral bioavailability of diphenhydramine is in the range of 40% to 60%, and peak plasma concentration occurs about 2 to 3 hours after administration. Diphenhydramine, available in various salt forms, such as citrate, hydrochloride, and salicylate, exhibits distinct molecular weights and pharmacokinetic properties. Specifically, diphenhydramine hydrochloride and diphenhydramine citrate possess molecular weights of 291.8 g/mol and 447.5 g/mol, respectively. These variations in molecular weight influence the dissolution rates and absorption characteristics of each salt form. The primary route of metabolism is two successive demethylations of the tertiary amine. The resulting primary amine is further oxidized to the carboxylic acid. Diphenhydramine is metabolized by the cytochrome P450 enzymes CYP2D6, CYP1A2, CYP2C9, and CYP2C19. The elimination half-life of diphenhydramine has not been fully elucidated, but appears to range between 2.4 and 9.3 hours in healthy adults. A 1985 review of antihistamine pharmacokinetics found that the elimination half-life of diphenhydramine ranged between 3.4 and 9.3 hours across five studies, with a median elimination half-life of 4.3 hours. A subsequent 1990 study found that the elimination half-life of diphenhydramine was 5.4 hours in children, 9.2 hours in young adults, and 13.5 hours in the elderly. A 1998 study found a half-life of 4.1 ± 0.3 hours in young men, 7.4 ± 3.0 hours in elderly men, 4.4 ± 0.3 hours in young women, and 4.9 ± 0.6 hours in elderly women.
For example, efavirenz and nelfinavir are two types of drugs that help decrease the HIV infection in a person's body. When the SNP from exon 26 is coupled with other SNP exons, the drugs have a lower chance of maintaining the HIV infection. Although, when the TT nucleotides in exon 26 are expressed the patient has a lower concentration of the virus but when the genotype morphs into CC or CT the infection is able to spread like normal leaving the MDR 1 gene almost defenseless. These changes in bases of exon 26 for MDR 1 show a correlation between the MDR 1 gene mutations and the ability of the antiretroviral drugs to suppress the HIV infection. Exon 26 has also been studied as to whether it is haplotype dependent or not. The presence of the SNP of exon 26 changes phenotypic functions when it is paired with the presence of mutations from exons 12 and 21. But when acting alone, it does not affect the phenotypic outcome as strongly. An example of exon 26's haplotype dependency is seen when looking at chemotherapy. Since MDR 1 removes drugs from our cells, inhibitors have been used to block MRD 1's ability to remove drugs, thus letting beneficial drugs like chemotherapy and immunosuppressants aid the body in recovery more efficiently. MDR1 has different proteins that help exile these specific drugs from cancer cells. Verapamil and cyclosporine A are common inhibitors for MDR 1.
Sources: en.wikipedia.org
== Most recent publications == Perez-Riverol, Yasset; Bai, Mingze; da Veiga Leprevost, Felipe; Squizzato, Silvano; Park, Young Mi; Haug, Kenneth; Carroll, Adam J; Spalding, Dylan; Paschall, Justin; Wang, Mingxun; del-Toro, Noemi; Ternent, Tobias; Zhang, Peng; Buso, Nicola; Bandeira, Nuno; Deutsch, Eric W; Campbell, David S; Beavis, Ronald C; Salek, Reza M; Sarkans, Ugis; Petryszak, Robert; Keays, Maria; Fahy, Eoin; Sud, Manish; Subramaniam, Shankar; Barbera, Ariana; Jiménez, Rafael C; Nesvizhskii, Alexey I; Sansone, Susanna-Assunta; Steinbeck, Christoph; Lopez, Rodrigo; Vizcaíno, Juan A; Ping, Peipei; Hermjakob, Henning (2017). "Discovering and linking public omics data sets using the Omics Discovery Index". Nature Biotechnology. 35 (5): 406–409. doi:10.1038/nbt.3790. ISSN 1087-0156. PMC 5831141. PMID 28486464. Omenn, Gilbert S.; Lane, Lydie; Lundberg, Emma K.; Beavis, Ronald C.; Overall, Christopher M.; Deutsch, Eric W. (2016). "Metrics for the Human Proteome Project 2016: Progress on Identifying and Characterizing the Human Proteome, Including Post-Translational Modifications". Journal of Proteome Research. 15 (11): 3951–3960. doi:10.1021/acs.jproteome.6b00511. ISSN 1535-3893. PMC 5129622. PMID 27487407. Spicer, Vic; Ezzati, Peyman; Neustaeter, Haley; Beavis, Ronald C.; Wilkins, John A.; Krokhin, Oleg V. (2016). "3D HPLC-MS with Reversed-Phase Separation Functionality in All Three Dimensions for Large-Scale Bottom-Up Proteomics and Peptide Retention Data Collection". Analytical Chemistry. 88 (5): 2847–2855. doi:10.1021/acs.analchem.5b04567. ISSN 0003-2700. PMID 26849966.
== Structure == In the yeast species Pichia pastoris, lysyl oxidase constitutes a homodimeric structure. Each monomer consists of an active site that includes a Cu(II) atom, coordinated by three histidine residues, as well as 2,4,5-trihydroxyphenylalanine quinone (TPQ), a crucial cofactor. In humans, the LOX gene is located on chromosome 5 q23.3-31.2. The DNA sequence encodes a polypeptide of 417 amino acids, the first 21 residues of which constitute a signal peptide, with a weight of approximately 32 kDa. The carboxyterminus contains the active copper (II) ion, lysine, tyrosine, and cysteine residues that comprise the catalytically active site. The three-dimensional structure of human lysyl oxidase has not yet been resolved.
Eventually, blood clots are reorganized and resorbed by a process termed fibrinolysis. The main enzyme responsible for this process is plasmin, which is regulated by plasmin activators and plasmin inhibitors.
== Track listing == "Sickman", "Junkhead", "Dirt" and "God Smack" are credited to Cantrell/Staley with no specification for lyrics or music. "Rain When I Die" is credited to Cantrell/Staley/Kinney/Starr, and it was later stated that Cantrell and Staley wrote the lyrics.
Sources: en.wikipedia.org
Dry powder is normally held at -20 degrees Celsius or below in a sealed, light-protected container with desiccant. Brief room-temperature handling during weighing is generally tolerated. Storage instructions vary between suppliers, so the accompanying certificate of analysis should be followed.
Reversed-phase HPLC establishes purity, while mass spectrometry confirms the expected molecular mass. Sequence confirmation may use tandem mass spectrometry or peptide mapping. A certificate of analysis typically reports these results alongside the analytical method applied.
In Russia it is a registered medicine available by prescription. In many other countries it is not approved for human use and is supplied only as a research chemical. Import and possession rules differ by jurisdiction, and buyers are responsible for checking local requirements.
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.