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Cyclooxygenase-1
Cyclooxygenase 1 (COX-1), also known as prostaglandin-endoperoxide synthase 1 (Human Genome Organisation, HUGO PTGS1), is an enzyme that in humans is encoded by the ''PTGS1'' gene. In humans it is one of Cyclooxygenase-3, three cyclooxygenases. History Cyclooxygenase (COX) is the central enzyme in the biosynthetic pathway to prostaglandins from arachidonic acid. This protein was isolated more than 40 years ago and Clone (genetics), cloned in 1988. Gene and isozymes There are two isozymes of COX encoded by distinct gene products: a constitutive COX-1 (this enzyme) and an inducible COX-2, which differ in their regulation of expression and tissue distribution. The expression of these two transcripts is differentially regulated by relevant cytokines and growth factors. This gene encodes COX-1, which regulates angiogenesis in endothelial cells. COX-1 is also involved in cell signaling and maintaining tissue Homeostasis#Overview, homeostasis. A splice variant of COX-1 termed COX-3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
COX-3
Cyclooxygenase-3 (COX-3) is an enzyme that is encoded by the ''PTGS1'' (''COX1'') gene, but is not functional in humans. COX-3 is the third and most recently discovered cyclooxygenase (COX3050) isozyme, while the first two to be discovered were COX-1 and COX-2. The COX-3 isozyme is encoded by the same gene as COX-1, with the difference that COX-3 retains an intron that is not retained in COX-1. The other two cyclooxygenase isozymes are known to convert dihomo-γ-linolenic acid and arachidonic acid into prostaglandins, and are the targets of nonsteroidal anti-inflammatory drugs (NSAIDs). Transcription COX-3 is transcribed from the ''PTGS1'' (''COX1'') gene, but the resulting mRNA is RNA splicing, spliced differently. In dogs the resulting protein resembles the other two COX enzymes, but in mice and humans it does not, owing to a frame-shift mechanism. This mechanism is due to the fact that the spliced intron has 93 bases in dogs, resulting in the loss of 93:3 = 31 amino acids in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Nonsteroidal Anti-inflammatory Drug
Non-steroidal anti-inflammatory drugs (NSAID) are members of a Indication (medicine), therapeutic drug class which Analgesic, reduces pain, Anti-inflammatory, decreases inflammation, Antipyretic, decreases fever, and Antithrombotic, prevents blood clots. Side effects depend on the specific drug, its dose and duration of use, but largely include an increased risk of Stomach ulcers, gastrointestinal ulcers and bleeds, heart attack, and kidney disease. The term ''non-steroidal'', common from around 1960, distinguishes these drugs from corticosteroids, another class of anti-inflammatory drugs, which during the 1950s had acquired a bad reputation due to overuse and side-effect problems after their introduction in 1948. NSAIDs work by inhibiting the activity of cyclooxygenase enzymes (the COX-1 and COX-2 isozyme, isoenzymes). In cells, these enzymes are involved in the synthesis of key biological mediators, namely prostaglandins, which are involved in inflammation, and thromboxanes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Cyclooxygenase
Cyclooxygenase (COX), officially known as prostaglandin-endoperoxide synthase (PTGS), is an enzyme (specifically, a family of isozymes, ) that is responsible for biosynthesis of prostanoids, including thromboxane and prostaglandins such as prostacyclin, from arachidonic acid. A member of the animal-type heme peroxidase family, it is also known as prostaglandin G/H synthase. The specific reaction catalyzed is the conversion from arachidonic acid to prostaglandin H2 via a short-living prostaglandin G2 intermediate. Pharmaceutical inhibition of COX can provide relief from the symptoms of inflammation and pain. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen, exert their effects through inhibition of COX. Those that are specific to the COX-2 isozyme are called COX-2 inhibitors. The active metabolite ( AM404) of paracetamol is a COX inhibitor, a fact to which some or all of its therapeutic effect has been attributed. In medicine, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Synthase
In biochemistry, a synthase is an enzyme that catalyses a synthesis process. Note that, originally, biochemical nomenclature distinguished synthetases and synthases. Under the original definition, synthases do not use energy from nucleoside triphosphates (such as ATP, GTP, CTP, TTP, and UTP), whereas synthetases do use nucleoside triphosphates. However, the Joint Commission on Biochemical Nomenclature (JCBN) dictates that 'synthase' can be used with any enzyme that catalyzes synthesis (whether or not it uses nucleoside triphosphates), whereas 'synthetase' is to be used synonymously with ' ligase'. Examples * ATP synthase * Citrate synthase * Tryptophan synthase * Pseudouridine synthase * Fatty acid synthase Fatty acid synthase (FAS) is an enzyme that in humans is encoded by the ''FASN'' gene. Fatty acid synthase is a multi-enzyme protein that catalyzes fatty acid synthesis. It is not a single enzyme but a whole enzymatic system composed of two ide ... * Cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
CYP2S1
Cytochrome P450 2S1 is a protein that in humans is encoded by the ''CYP2S1'' gene. The gene is located in chromosome 19q13.2 within a cluster including other CYP2 family members such as CYP2A6, CYP2A13, CYP2B6, and CYP2F1. Expression CYP2S1 is highly expressed in epithelial tissues of the respiratory, gastrointestinal, urinary tracts, and skin and in leukocytes of the monocyte/macrophage and lymphocyte series; it is also expressed throughout Embryogenesis and, as discussed below, certain types of cancers. Function This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This protein localizes to the endoplasmic reticulum. In rodents, the homologous protein has been shown to metabolize certain carcinogens although its specific function(s) in humans has not been clearly determined. In in vitro studies, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Malonyldialdehyde
Malondialdehyde belong to the class of β-dicarbonyls. A colorless solid, malondialdehyde is a highly reactive compound that occurs as the enol. It is a physiological metabolite, and a marker for oxidative stress. Structure and synthesis Malondialdehyde mainly exists as its enol, hydroxyacrolein:V. Nair, C. L. O'Neil, P. G. Wang "Malondialdehyde", ''Encyclopedia of Reagents for Organic Synthesis'', 2008, John Wiley & Sons, New York. Article Online Posting Date: March 14, 2008 :CH2(CHO)2 → HOC(H)=CH-CHO In organic solvents, the ''cis''-isomer is favored, whereas in water the ''trans''-isomer predominates. The equilibrium is rapid and is inconsequential for many purposes. In the laboratory it can be generated in situ by hydrolysis of its acetal 1,1,3,3-tetramethoxypropane, which is commercially available and shelf-stable, unlike malondialdehyde. Malondialdehyde is easily deprotonated to give the sodium salt of the enolate (m.p. 245 °C). Biosynthesis and reactivit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
12-Hydroxyheptadecatrienoic Acid
12-Hydroxyheptadecatrienoic acid (also termed 12-HHT, 12(''S'')-hydroxyheptadeca-5''Z'',8''E'',10''E''-trienoic acid, or 12(S)-HHTrE) is a 17 carbon metabolite of the 20 carbon polyunsaturated fatty acid, arachidonic acid. 12-HHT is less ambiguously termed 12-(''S'')-hydroxy-5''Z'',8''E'',10''E''-heptadecatrienoic acid to indicate the ''S'' stereoisomerism of its 12-hydroxyl residue and the ''Z'', ''E'', and ''E'' cis–trans isomerism of its three double bonds. 12-HHT was discovered and structurally defined in 1973 by , Bengt Samuelsson, and Mats Hamberg. It was identified as a product of arachidonic acid metabolism made by microsomes isolated from sheep seminal vesicle glands and by intact human platelets. 12-HHT was for many years thought to be merely a biologically inactive byproduct of prostaglandin synthesis. More recent studies, however, have attached potentially important activity to it. Production Primary source Cyclooxygenase-1 and cyclooxygenase-2 metabolize ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Lipoxins
A lipoxin (LX or Lx), an acronym for lipoxygenase interaction product, is a bioactive autacoid metabolite of arachidonic acid made by various cell types. They are categorized as nonclassic eicosanoids and members of the specialized pro-resolving mediator (SPM) family of polyunsaturated fatty acid (PUFA) metabolites. Like other SPMs, LXs form during an inflammatory response and act to resolve it. The first lipoxins identified were lipoxin A4 (LXA4) and lipoxin B4 (LXB4), followed by their respective epimers, the epi-lipoxins 15-epi-LXA4 and 15-epi-LXB4. History LXA4 and LXB4 were first described by Charles Serhan, Mats Hamberg, and Bengt Samuelsson in 1984. They reported that human blood neutrophils, when stimulated, make these two lipoxins and that neutrophils, when stimulated by either of the LXs, mounted superoxide anion (O2−) generation and degranulation responses. Both responses are considered to be pro-inflammatory in that, while aimed at neutralizing invading pathog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Stereoisomers
In stereochemistry, stereoisomerism, or spatial isomerism, is a form of isomerism in which molecules have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in space. This contrasts with structural isomers, which share the same molecular formula, but the bond connections or their order differs. By definition, molecules that are stereoisomers of each other represent the same structural isomer. Enantiomers Enantiomers, also known as optical isomers, are two stereoisomers that are related to each other by a reflection: they are mirror images of each other that are non-superposable. Human hands are a macroscopic analog of this. Every stereogenic center in one has the opposite configuration in the other. Two compounds that are enantiomers of each other have the same physical properties, except for the direction in which they rotate polarized light and how they interact with different enantiomers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
15-Hydroxyicosatetraenoic Acid
15-Hydroxyeicosatetraenoic acid (also termed 15-HETE, 15(''S'')-HETE, and 15''S''-HETE) is an eicosanoid, i.e. a metabolite of arachidonic acid. Various cell types metabolize arachidonic acid to 15(''S'')-hydroperoxyeicosatetraenoic acid (15(''S'')-HpETE). This initial Peroxide, hydroperoxide product is extremely short-lived in cells: if not otherwise metabolized, it is rapidly reduced to 15(''S'')-HETE. Both of these metabolites, depending on the cell type which forms them, can be further metabolized to 15-oxo-eicosatetraenoic acid (15-oxo-ETE), 5(''S''),15(''S'')-dihydroxy-eicosatetraenoic acid (5(''S''),15(''S'')-diHETE), 5-oxo-15(''S'')-hydroxyeicosatetraenoic acid (5-oxo-15(''S'')-HETE), a subset of specialized pro-resolving mediators viz., the lipoxins, a class of pro-inflammatory mediators, the eoxins, and other products that have less well-defined activities and functions. Thus, 15(''S'')-HETE and 15(''S'')-HpETE, in addition to having intrinsic biological activities, are ke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
PGG2
Prostaglandin G2 (PGG2) is an organic peroxide belonging to the family of prostaglandins. The compound has been isolated as a solid, although it is usually used in vivo. It quickly converts into prostaglandin H2, a process catalyzed by the enzyme cyclooxygenase (COX). Prostaglandin G2 is produced from the fatty acid arachidonic acid Arachidonic acid (AA, sometimes ARA) is a polyunsaturated omega−6 fatty acid 20:4(ω−6), or 20:4(5,8,11,14). It is a precursor in the formation of leukotrienes, prostaglandins, and thromboxanes. Together with omega−3 fatty acids an .... The reaction, a double oxygenation, requires the enzyme COX, which inserts two molecules of O2 into the C-H bonds of the substrate acid. References Prostaglandins {{alkanederivative-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
