Methionine oxidation 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.
Updated 2025-11-26. Numbers and descriptions here follow the published literature rather than marketing material.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Analog of an ACTH fragment |
| Amino acid length | Seven residues | Met-Glu-His-Phe-Pro-Gly-Pro |
| Origin | Moscow, 1980s | Institute of Molecular Genetics |
| Approved regions | Russia and some neighboring states | Not cleared in Western markets |
| Common trade names | Multiple national brands | Sold as a nasal formulation |
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
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.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
These activities all require energy and, thus, use glucose; basal rate must decrease in order to keep glucose levels high enough to be used as fuel for the body. On the other hand, fevers, having a cold, taking a nap, taking cortisone-containing medication, and moments of excitement call for different basal rate needs. In these instances, the body has an overwhelming supply of glucose, and glucose levels need to decrease. To induce this decrease, basal rate needs to increase to increase insulin release to absorb some of the excess glucose from the blood stream. Those with diabetes mellitus must be aware of their basal rates and regulate them accordingly. Basal rate can be raised and lowered through various methods. For example, individuals with diabetes mellitus often use an insulin pump to supply an increased amount of insulin into the blood stream. Those with diabetes also may eat carbohydrates or sugars to account for low blood sugar. However one monitors and regulates their blood sugar levels and basal rates, it is important to make changes gradually. An initial lowering in basal rate should be no more than 10% of the original. After the initial lowering point, one must note the factor by which one's blood sugar changes. If blood sugar levels decreased, one should lower their basal rate by 20% next time. If their blood sugar levels increased, a lowering of 10% was too great, and one should not lower their basal rate at all next time. If blood sugar levels remained relatively constant, a drop in basal rate of 10% was sufficient.
== Antimicrobial peptides == Antimicrobial Peptides (AMPs) have gained attention because they are much less susceptible to the development of microbial resistance. Other antibiotics may be susceptible to bacterial resistance, like multi-resistant staphylococcus aureus (MRSA) which is known as a common relic in the healthcare industry while other bacterial strains have become more of a concern for waste water treatment in local rivers or bays. AMPs can be functionalized onto a surface by either chemical or physical attachment. AMPs can be physically attached by using oppositely charged polymeric layers and sandwiching the polypeptide between them. This may be repeated to achieve multiple layers of AMPs for the recurring antibacterial activity. There are a few drawbacks to this mechanism. Assembly thickness and polymer-peptide interactions can affect the diffusion of peptide to bacterial contact. Further research should be carried out to determine the effectiveness of the adsorption technique. However, the chemical attachment of AMPs is also widely studied. AMPs can be covalently bound to a surface, which minimizes the "leaching effect" of peptides. The peptide is typically attached by a very exergonic chemical reaction, thus forming a very stable antimicrobial surface. The surface can be functionalized first with a polymer resin such as polyethylene glycol (PEG). Recent research has focused on producing synthetic polymers and nanomaterials with similar mechanisms of action to endogenous antimicrobial peptides.
This will invoke the component's search function, passing "your query" and "strict" as arguments. This type of invocation is well-suited for Ajax-enabled applications. ColdFusion 8 introduced the ability to serialize ColdFusion data structures to JSON for consumption on the client. The ColdFusion server will automatically generate documentation for a component if you navigate to its URL and insert the appropriate code within the component's declarations. This is an application of component introspection, available to developers of ColdFusion components. Access to a component's documentation requires a password. A developer can view the documentation for all components known to the ColdFusion server by navigating to the ColdFusion URL. This interface resembles the Javadoc HTML documentation for Java classes.
Sources: en.wikipedia.org
=== Singer-songwriter === In 1996, Sheik released his self-titled debut album, which was certified gold. The album featured the hit single "Barely Breathing", which peaked at number 16 and remained on the Billboard Hot 100 for 55 consecutive weeks. "Barely Breathing" also enjoyed Top 20 success on Adult Contemporary radio, reached No. 2 on the Adult Top 40 charts, and garnered Sheik a Grammy Award nomination for Best Male Pop Vocal Performance. In 1998, Sheik recorded "Embraceable You" for Red Hot + Rhapsody, a George Gershwin tribute, and also recorded "Songbird" for another tribute, Legacy: A Tribute to Fleetwood Mac's Rumours. Also in 1998, Sheik released Humming, which featured orchestral and string arrangements. Sheik sang a duet with singer Howard Jones on Jones' 2000 single entitled Someone You Need. He released Phantom Moon, a Nick Drake-influenced album created in collaboration with poet and playwright Steven Sater, in 2001. The following year, Sheik released Daylight, which included the singles "On a High" and "Half-Life". After a four-year recording break, Sheik released White Limousine (2006), which included a DVD allowing listeners to remix and reinterpret songs from the album. In 2009, he released Whisper House, a concept album which provided the score for the musical of the same name. The stage musical premiered at The Old Globe Theatre in San Diego in January 2010, after a workshop at Vassar College, produced by New York Stage and Film in 2009. In 2011, Sheik released Covers 80s, an album including covers of popular 1980s songs.
== Measurement techniques == DHR can be determined with a combination of different preparation techniques and instruments for different purposes. There are several types of HIC measurement: (i) organic hydrogen or water are converted to H2 first, followed by high-precision isotope-ratio mass spectrometry (IRMS) measurement; (ii) 2H/1H and 18O/16O are directly measured as H2O by laser spectroscopy also with high precision; (iii) the intact molecules are directly measured by NMR or mass spectrometry with lower precision than IRMS.
== Overview == The process that converts the chemical energy of food into ATP (which can release energy) is not dependent on oxygen availability. During exercise, the supply and demand of oxygen available to muscle cells is affected by duration and intensity and by the individual's cardio respiratory fitness level. It is also affected by the type of activity, for instance, during isometric activity the contracted muscles restricts blood flow (leaving oxygen and blood borne fuels unable to be delivered to muscle cells adequately for oxidative phosphorylation). Three systems can be selectively recruited, depending on the amount of oxygen available, as part of the cellular respiration process to generate ATP for the muscles. They are ATP, the anaerobic system and the aerobic system.
Sources: en.wikipedia.org
Some childhood memories made lifelong impressions on him. As a boy, he carved a tiny mannequin into the end of the wooden ruler from his pencil case and placed it inside it. He added a stone, which he had painted into the upper and lower halves, and hid the case in the attic. Periodically, he would return to the mannequin, often bringing tiny sheets of paper with messages inscribed on them in his own secret language. He later reflected that this ceremonial act brought him a feeling of inner peace and security. Years later, he discovered similarities between his personal experience and the practices associated with totems in Indigenous cultures, such as the collection of soul-stones near Arlesheim or the tjurungas of Australia. He concluded that his intuitive ceremonial act was an unconscious ritual, which he had practiced in a way that was strikingly similar to those in distant locations which he, as a young boy, knew nothing about. His observations about symbols, archetypes, and the collective unconscious were inspired, in part, by these early experiences combined with his later research. At the age of 12, shortly before the end of his first year at the Humanistisches Gymnasium in Basel, Jung was pushed to the ground by another boy and hit his head, momentarily losing consciousness (he later recognised the incident was indirectly his fault). A thought then came to him—"Now you won't have to go to school anymore". From then on, whenever he walked to school or began homework, he fainted.
Dover grew further after the Norman invasion of 1066 as a member of the Confederation of Cinque Ports. After the martyrdom of Archbishop Thomas Becket at Canterbury Cathedral in 1170, Dover flourished as the only designated port of entry for foreign pilgrims and as a point of departure for the third and subsequent crusades. Following Edward III's success at the Battle of Sluys in 1340, a large defensive wall was built around the town. Although few concerted attempts to manage the shingle deposits blocking the harbour entrance were made during the late Middle Ages, a short pier and two defensive towers were constructed at the port in years immediately prior to Henry VIII's departure to the royal summit known as the Field of the Cloth of Gold in 1520.
== Y == Yam – indigenous Americans in the Guyana region of South America domesticated the most important New World yam: D. Trifada Yucca – the plant was cultivated throughout the Americas, and is mostly distributed in coastal lowlands and dry beach scrub of coastal areas.
In oxidative phosphorylation, electrons are transferred from an electron donor such as NADH to an acceptor such as O2 through an electron transport chain, releasing energy. In photophosphorylation, the energy of sunlight is used to create a high-energy electron donor which can subsequently reduce oxidized components and couple to ATP synthesis via proton translocation by the electron transport chain. Photosynthetic electron transport chains, like the mitochondrial chain, can be considered as a special case of the bacterial systems. They use mobile, lipid-soluble quinone carriers (phylloquinone and plastoquinone) and mobile, water-soluble carriers (cytochromes). They also contain a proton pump. The proton pump in all photosynthetic chains resembles mitochondrial Complex III. The commonly held theory of symbiogenesis proposes that both organelles descended from bacteria.
Sources: en.wikipedia.org
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.
It is registered as a medicine in Russia and has been used clinically there for decades. No regulatory agency in Western Europe or North America has approved it for any indication.
Semax corresponds to the four-to-ten fragment of adrenocorticotropic hormone. Because it omits the first three residues, it lacks the adrenal-stimulating action of the full hormone.
Dry powder is normally held at -20 °C or lower, away from light and moisture. Sealed vials can also be kept at 2-8 °C for shorter intervals. Warming to room temperature before opening prevents condensation.