This is a working overview of heptapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-08-17 and is reviewed periodically as new material appears.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
| Property | Value | Notes |
|---|---|---|
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Heptapeptide; ACTH(4-10) analog extended at C-terminus |
| Molecular mass | ~813.9 Da | Free peptide, unmodified |
| Appearance | White to off-white powder | Typical lyophilized solid |
| Solubility | Soluble in water and saline | Also soluble in common aqueous buffers |
| Storage (solid) | -20 °C, desiccated | Protect from moisture and repeated thawing |
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
== Mechanism of resistance == Streptogramin resistance is mediated through enzymatic drug inactivation, efflux or active transport of drug out of the cell, and most commonly, conformational alterations in ribosomal target binding sites. Enzymatic drug inactivation may occur in staphylococcal and enterococcal species through production of dalfopristin-inactivating acetyltransferase or quinupristin-inactivating hydrolase. Efflux or active transport of the drug may occur in coagulase-negative staphylococci and Enterococcus faecium. Constitutive ribosome modification has been seen in staphylococci with resistance seen in quinupristin only. While resistance to dalfopristin may be conferred via a single point of mutation, quinupristin/dalfopristin offers the benefit of requiring multiple points of mutation targeting both dalfopristin and quinupristin components to confer drug resistance. Comparatively, only 2-5% of staphylococcal isolates collected in France show resistance to a related streptogramin, pristinamycin, in over 35 years of use.
== Types == The glomerular basement membrane of the kidney, is an unusually thick basement membrane. It serves as part of a molecular filter that prevents macromolecules from the blood from entering the urine. It is faced by a cell layer on either side, the endothelium, and the podocytes, and has a thicker structure of three laminae. It is thicker by the fusion of the basal lamina from the endothelium of glomerular capillaries and the podocyte basal lamina. These layers are known as the central lamina densa, and on each side, a lamina rara – a lamina rara interna facing the endothelium, and a lamina rara externa facing the podocytes. In the lung the basement membrane of the alveolus and that of the surrounding capillary are fused, allowing an easy exchange of gases. In the mucosae the basement membrane lies between one or more layers of epithelial cells that it supports, and the underlying attached loose connective tissue called the lamina propria.
Lipidomics is the large-scale study of pathways and networks of cellular lipids in biological systems. The word "lipidome" is used to describe the complete lipid profile within a cell, tissue, organism, or ecosystem and is a subset of the "metabolome" which also includes other major classes of biological molecules (such as amino acids, sugars, glycolysis & TCA intermediates, and nucleic acids). Lipidomics is a relatively recent research field that has been driven by rapid advances in technologies such as mass spectrometry (MS), nuclear magnetic resonance (NMR) spectroscopy, fluorescence spectroscopy, dual polarisation interferometry and computational methods, coupled with the recognition of the role of lipids in many metabolic diseases such as obesity, atherosclerosis, stroke, hypertension and diabetes. This rapidly expanding field complements the huge progress made in genomics and proteomics, all of which constitute the family of systems biology. Lipidomics research involves the identification and quantification of the thousands of cellular lipid molecular species and their interactions with other lipids, proteins, and other metabolites. Investigators in lipidomics examine the structures, functions, interactions, and dynamics of cellular lipids and the changes that occur during perturbation of the system. Han and Gross first defined the field of lipidomics through integrating the specific chemical properties inherent in lipid molecular species with a comprehensive mass spectrometric approach.
Instead, it is suggested "that desmosine may be more useful in understanding the pathogenesis of ALI and less useful as a marker of disease severity.” The current standard for measuring lung disease progression, for example, is measured through the forced expiratory volume in one second (FEV1) compared to the maximum lung capacity; in other words, the volume of air a person can exhale from full lungs in one second compared to their maximum lung capacity. This method, while simple and physiologically thorough, has biological limitations, and so a superior biological marker is being sought after. Desmosine has been studied as one such biological marker, with studies in the 1980s to link urinary desmosine concentration with elastin breakdown in the lungs. Though large amounts of data have been collected with regards to desmosine's potential as a replacement biological marker in determining disease progression, some believe there is still insufficient evidence for desmosine to meet and fill this need. In orthopedics, one study examined equine tendons and how their increasing stiffness and fatigue with age was due to fragmentation of the elastin in the tendons. The superficial digital flexor tendon (SDFT) and the common digital extensor tendon (CDET) were analyzed for elastin composition, comparing older tendons to younger ones.
Sources: en.wikipedia.org
== Meetings == The APS organizes a four-day annual meeting called the Lorne Proteomics Symposium, traditional starting on the first Thursday of February, in Lorne, Victoria. In addition, the APS is active in organizing other symposia both in Australia and in New Zealand.
A glycome is the entire complement or complete set of all sugars, whether free or chemically bound in more complex molecules, of an organism. An alternative definition is the entirety of carbohydrates in a cell. The glycome may in fact be one of the most complex entities in nature. "Glycomics, analogous to genomics and proteomics, is the systematic study of all glycan structures of a given cell type or organism" and is a subset of glycobiology. "Carbohydrate", "glycan", "saccharide", and "sugar" are generic terms used interchangeably in this context and includes monosaccharides, oligosaccharides, polysaccharides, and derivatives of these compounds. Carbohydrates consist of "hydrated carbon", i.e. [CH2O]n. Monosaccharides are a carbohydrate that cannot be hydrolyzed into a simpler carbohydrate and are the building blocks of oligosaccharides and polysaccharides. Oligosaccharides are linear or branched chains of monosaccharides attached to one another via glycosidic linkages. The number of monosaccharide units can vary. Polysaccharides are glycans composed of repeating monosaccharides, generally greater than ten monosaccharide units in length. The glycome exceeds the complexity of the proteome as a result of the even greater diversity of the glycome's constituent carbohydrates and is further complicated by the sheer multiplicity of possibilities in the combination and interaction of the carbohydrates with each other and with proteins. "The spectrum of all glycan structures — the glycome — is immense.
=== Aliases === As with many other genes, there are some common aliases found with this gene. Those aliases are Lymphocyte-Activation Gene-1 (LAG1) Interacting Protein, Transparent Testa Glabra 1 (TTG1), and Odorant Response Abnormal 4 (ODR4). The most common alias for C1orf27 is ODR4, and this is what most readily appears when searching the gene.
The xanthophyll cycle involves the enzymatic removal of epoxy groups from xanthophylls (e.g. violaxanthin, antheraxanthin, diadinoxanthin) to create so-called de-epoxidised xanthophylls (e.g. diatoxanthin, zeaxanthin). These enzymatic cycles were found to play a key role in stimulating energy dissipation within light-harvesting antenna proteins by non-photochemical quenching- a mechanism to reduce the amount of energy that reaches the photosynthetic reaction centers. Non-photochemical quenching is one of the main ways of protecting against photoinhibition. In higher plants, there are three carotenoid pigments that are active in the xanthophyll cycle: violaxanthin, antheraxanthin, and zeaxanthin. During light stress, violaxanthin is converted, i.e. reduced, to zeaxanthin via the intermediate antheraxanthin, which plays a direct photoprotective role acting as a lipid-protective anti-oxidant and by stimulating non-photochemical quenching within light-harvesting proteins. This conversion of violaxanthin to zeaxanthin is done by the enzyme violaxanthin de-epoxidase (EC 1.23.5.1), while the reverse reaction, i.e. oxidation, is performed by zeaxanthin epoxidase (EC 1.14.15.21). In diatoms and dinoflagellates, the xanthophyll cycle consists of the pigment diadinoxanthin, which is transformed into diatoxanthin (diatoms) or dinoxanthin (dinoflagellates) under high-light conditions. Wright et al.
=== Inflammation === Neuroinflammation is considered a contributing mechanism in Parkinson's disease. Research has shown lasting activation of the brain's immune cells, microglia, in regions affected by the disease, suggesting that inflammation may play a role in the gradual loss of dopamine-producing neurons. While immune responses can be protective in the short term, chronic inflammation may damage neurons over time. Dopaminergic neurons appear to be particularly vulnerable under inflammatory conditions. The normal production and breakdown of dopamine already place these cells under higher stress than other neurons. When inflammation is present, this may increase the neurons' susceptibility to damage and speed up degeneration. Changes in dopamine signaling may then influence immune activity in the brain, creating a feedback loop to further worsen neuronal loss.
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vasoconstriction temporary blockage of a hole in a damaged blood vessel by a platelet plug blood coagulation (formation of fibrin clots) Coagulation, the changing of blood from a liquid to a gel which forms the fibrin clots, is essential to hemostasis. Intact blood vessels moderate blood's tendency to form clots. The endothelial cells of intact vessels prevent blood clotting with a heparin-like molecule and thrombomodulin, and prevent platelet aggregation with nitric oxide and prostacyclin. When endothelium of a blood vessel is damaged, the endothelial cells stop secretion of coagulation and aggregation inhibitors and instead secrete von Willebrand factor, which initiates the maintenance of hemostasis after injury. These processes seal the injury or hole until tissues are healed.
Austin was involved in the concluding segment at ECW One Night Stand on June 12 in which he had a beer bash with the ECW locker room. He also appeared on the internet themed event Cyber Sunday in 2007 and 2008. Austin also made appearenced to promote WWE material, like the WWE Films' production The Condemned, the revival of Tough Enough in 2011.
Three of the four outer-shell electrons of each atom in a graphene sheet occupy three sp2 hybrid orbitals – a combination of orbitals s, px and py — that are shared with the three nearest atoms, forming σ-bonds. The length of these bonds is about 0.142 nanometers. The remaining outer-shell electron occupies a pz orbital that is oriented perpendicularly to the plane. These orbitals hybridize together to form two half-filled bands of free-moving electrons, π, and π∗, which are responsible for most of graphene's notable electronic properties. Recent quantitative estimates of aromatic stabilization and limiting size derived from the enthalpies of hydrogenation (ΔHhydro) agree well with the literature reports. Graphene sheets stack to form graphite with an interplanar spacing of 0.335 nm (3.35 Å). Graphene sheets in solid form usually show evidence in diffraction for graphite's (002) layering. This is true of some single-walled nanostructures. However, unlayered graphene displaying only (hk0) rings have been observed in the core of presolar graphite onions. TEM studies show faceting at defects in flat graphene sheets and suggest a role for two-dimensional crystallization from a melt.
=== Acute inflammation === When there is a stimulus, the CRP level can increase 10,000-fold from less than 50 μg/L to more than 500 mg/L. Its concentration can increase to 5 mg/L by 6 hours and peak at 48 hours. The plasma half-life of CRP is 19 hours, and is constant in all medical conditions. Therefore, the only factor that affects the blood CRP concentration is its production rate, which increases with inflammation, infection, trauma, necrosis, malignancy, and allergic reactions. Other inflammatory mediators that can increase CRP are TGF beta 1, and tumor necrosis factor alpha. In acute inflammation, CRP can increase as much as 50 to 100 mg/L within 4 to 6 hours in mild to moderate inflammation or an insult such as skin infection, cystitis, or bronchitis. It can double every 8 hours and reaches its peak at 36 to 50 hours following injury or inflammation. CRP between 100 and 500 mg/L is considered highly predictive of inflammation due to bacterial infection. Once inflammation subsides, CRP level falls quickly because of its relatively short half-life.
Sources: en.wikipedia.org
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.
Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.
It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.