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Dipeptide
A dipeptide is an organic compound derived from two amino acids. The constituent amino acids can be the same or different. When different, two isomers of the dipeptide are possible, depending on the sequence. Several dipeptides are physiologically important, and some are both physiologically and commercially significant. A well known dipeptide is aspartame, an artificial sweetener. Dipeptides are white solids. Many are far more water-soluble than the parent amino acids. For example, the dipeptide Ala-Gln has the solubility of 586 g/L more than 10x the solubility of Gln (35 g/L). Dipeptides also can exhibit different stabilities, e.g. with respect to hydrolysis. Gln does not withstand sterilization procedures, whereas this dipeptide does. Because dipeptides are prone to hydrolysis, the high solubility is exploited in infusions, i.e. to provide nutrition. Examples Commercial value About six dipeptides are of commercial interest. *Aspartame (''N''-L-α-aspartyl-L-phenyl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudoproline
Pseudoproline (also pseudo-proline, ψ-Pro) derivatives are artificially created dipeptides to minimize aggregation during Fmoc solid-phase synthesis of peptides. History The chemical synthesis of large peptides is still limited by problems of low solvation during solid phase peptide synthesis (SPPS) or limited solubility of fully protected peptide fragments: even chemoselective ligation methods are hampered by self-association of unprotected peptide blocks. The elucidation of the relationship between preferred conformation of a growing peptide chain and its physicochemical properties reveals that β-sheet (beta-sheet) formation is often paralleled by significant decrease in solvation and solubility. Besides attempts to increase the solvation of peptides by external factors, few attempts, i.e. N-substituted Hmb amino acid derivatives and pseudoprolines (see figure on the top right) have been reported to modify the intrinsic properties of peptides responsible for aggregation and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ala-Gln
Alanyl-glutamine is a chemical compound which in the form L-alanyl-L-glutamine is used in dietary supplementation, in parenteral nutrition, and in cell culture. It is a dipeptide consisting of alanine and glutamine. Dieterary supplement As a dietary supplement, alanyl-glutamine protects the gastrointestinal tract. The protective effect reduces bacterial translocation, thus reducing the risk of infections and infection-related problems such as diarrhea, dehydration, malabsorption, and electrolyte imbalance. Parenteral nutrition At room temperature with 1 atmosphere of pressure, L-alanyl-L-glutamine has a solubility of about 586 g/L, which is more than 10 times glutamine's solubility (35 g/L). Also, glutamine does not withstand sterilization procedures, whereas alanyl-glutamine does. Alanyl-glutamine's high solubility makes it valuable in parenteral nutrition. Cell culture In cell culture, L-alanyl-L-glutamine is sometimes used as a replacement for L-glutamine because th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspartame
Aspartame is an artificial non- saccharide sweetener 200 times sweeter than sucrose and is commonly used as a sugar substitute in foods and beverages. It is a methyl ester of the aspartic acid/phenylalanine dipeptide with the trade names ''NutraSweet'', ''Equal'', and ''Canderel''. First submitted for approval as a food ingredient in 1974, aspartame was approved by the US Food and Drug Administration (FDA) in 1981. Aspartame is one of the most rigorously tested food ingredients. Reviews by over 100 governmental regulatory bodies found the ingredient safe for consumption at current levels.Food Standards Australia New Zealand: , several reviews of clinical trials showed that using aspartame in place of sugar reduces calorie intake and body weight in adults and children. Uses Aspartame is around 180 to 200 times sweeter than sucrose (table sugar). Due to this property, even though aspartame produces of energy per gram when metabolized, the quantity of asparta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspartame
Aspartame is an artificial non- saccharide sweetener 200 times sweeter than sucrose and is commonly used as a sugar substitute in foods and beverages. It is a methyl ester of the aspartic acid/phenylalanine dipeptide with the trade names ''NutraSweet'', ''Equal'', and ''Canderel''. First submitted for approval as a food ingredient in 1974, aspartame was approved by the US Food and Drug Administration (FDA) in 1981. Aspartame is one of the most rigorously tested food ingredients. Reviews by over 100 governmental regulatory bodies found the ingredient safe for consumption at current levels.Food Standards Australia New Zealand: , several reviews of clinical trials showed that using aspartame in place of sugar reduces calorie intake and body weight in adults and children. Uses Aspartame is around 180 to 200 times sweeter than sucrose (table sugar). Due to this property, even though aspartame produces of energy per gram when metabolized, the quantity of asparta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha amino acids appear in the genetic code. Amino acids can be classified according to the locations of the core structural functional groups, as Alpha and beta carbon, alpha- , beta- , gamma- or delta- amino acids; other categories relate to Chemical polarity, polarity, ionization, and side chain group type (aliphatic, Open-chain compound, acyclic, aromatic, containing hydroxyl or sulfur, etc.). In the form of proteins, amino acid '' residues'' form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kyotorphin
Kyotorphin (L-tyrosyl-L-arginine) is a neuroactive dipeptide which plays a role in pain regulation in the brain. It was first isolated from bovine brain, by Japanese scientists in 1979. Kyotorphin was named for the site of its discovery, Kyoto, Japan and because of its morphine- (or endorphin-) like analgesic activity. Kyotorphin has an analgesic effect, but it does not interact with the opioid receptors. Instead, it acts by releasing met-enkephalin and stabilizing it from degradation. It may also possess properties of neuromediator/neuromodulator. It has been shown that kyotorphin is present in the human cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates. CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the ... and that its concentration is lower in patients with persistent pain. References {{Opioidergics Dipeptid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycylglycine
Glycylglycine is the dipeptide of glycine, making it the simplest peptide Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. .... The compound was first synthesized by Emil Fischer and Ernest Fourneau in 1901 by boiling 2,5-diketopiperazine (glycine anhydride) with hydrochloric acid. Shaking with alkali and other synthesis methods have been reported. Because of its low toxicity, it is useful as a buffer for biological systems with effective ranges between pH 2.5–3.8 and 7.5–8.9; however, it is only moderately stable for storage once dissolved. It is used in the synthesis of more complex peptides. Glycylglycine has also been reported to be helpful in solubilizing recombinant proteins in ''E. coli''. Using different concentrations of the glycylglycine improvement in protein solub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carnosine
Carnosine (''beta''-alanyl-L-histidine) is a dipeptide molecule, made up of the amino acids beta-alanine and histidine. It is highly concentrated in muscle and brain tissues. Carnosine was discovered by Russian chemist Vladimir Gulevich. Carnosine is naturally produced by the body in the liver from beta-alanine and histidine. Like carnitine, carnosine is composed of the root word ''carn'', meaning "flesh", alluding to its prevalence in meat. There are no plant-based sources of carnosine. Carnosine is readily available as a synthetic nutritional supplement. Biosynthesis Carnosine is synthesized within the body from beta-alanine and histidine. Beta-alanine is a product of pyrimidine catabolism and histidine is an essential amino acid. Since beta-alanine is the limiting substrate, supplementing just beta-alanine effectively increases the intramuscular concentration of carnosine. Physiological effects pH buffer Carnosine has a pKa value of 6.83, making it a good buffer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphenylalanine
Diphenylalanine is a term that has recently been used to describe the unnatural amino acid similar to the two amino acids alanine and phenylalanine. It has been used for the synthesis of pseudopeptide analogues which are capable of inhibiting certain enzymes. Individual enantiomers of this compound can be synthesized via electrophilic amination of a chiral oxazolidinone derivative of 3,3-diphenylpropanoic acid. A historical use of the term ''diphenylalanine'' refers to the dipeptide A dipeptide is an organic compound derived from two amino acids. The constituent amino acids can be the same or different. When different, two isomers of the dipeptide are possible, depending on the sequence. Several dipeptides are physiological ... of phenylalanine (). References Amino acids {{amine-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slime Mold
Slime mold or slime mould is an informal name given to several kinds of unrelated eukaryotic organisms with a life cycle that includes a free-living single-celled stage and the formation of spores. Spores are often produced in macroscopic multicellular or multinucleate fruiting bodies which may be formed through aggregation or fusion. Slime molds were formerly classified as fungi but are no longer considered part of that kingdom (biology), kingdom. Although not forming a single Clade, monophyletic clade, they are grouped within the paraphyly, paraphyletic group Protists, Protista. More than 900 species of slime mold occur globally. Their common name refers to part of some of these organisms' life cycles where they can appear as gelatinous "slime". This is mostly seen with the Myxogastria, which are the only Macroscopic scale, macroscopic slime molds. Most slime molds are smaller than a few centimetres, but some species may reach sizes up to several square metres and masses up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barettin
Barettin is a brominated alkaloid made of a dehydrogenated brominated derivative of tryptophan linked by two peptide bonds to an arginine residue, forming a 2,5-diketopiperazine nucleus. It is a cyclic dipeptide. Barettin is the major compound in the deep-sea sponge ''Geodia barretti ''Geodia barretti'' is a massive deep-sea sponge species found in the boreal waters of the North Atlantic Ocean, and is fairly common on the coasts of Norway and Sweden. It is a dominant species in boreal sponge grounds. Supported by morphology ...''. It was isolated for the first time in 1986 by Göran Lidgren, Lars Bohlin and Jan Bergman at Uppsala University, Sweden but the correct chemical structure was determined later in 2002. Barettin is written with one 'r' because the authors misspelled ''Geodia barretti'' with one 'r' in the original paper. Barettin seems to show antioxidant and anti-inflammatory properties which could be used in treating diseases that affect the immune system and dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic Peptide
Cyclic peptides are polypeptide chains which contain a circular sequence of bonds. This can be through a connection between the amino and carboxyl ends of the peptide, for example in cyclosporin; a connection between the amino end and a side chain, for example in bacitracin; the carboxyl end and a side chain, for example in colistin; or two side chains or more complicated arrangements, for example in amanitin. Many cyclic peptides have been discovered in nature and many others have been synthesized in the laboratory. Their length ranges from just two amino acid residues to hundreds. In nature they are frequently antimicrobial or toxic; in medicine they have various applications, for example as antibiotics and immunosuppressive agents. Thin-Layer Chromatography (TLC) is a convenient method to detect cyclic peptides in crude extract from bio-mass. Classification Cyclic peptides can be classified according to the types of bonds that comprise the ring. *Homodetic cyclic peptides, su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
