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M7G(5')pppN Diphosphatase
In enzymology, a m7G(5')pppN diphosphatase or m7G(5')pppN pyrophosphatase () is an enzyme that catalyzes the chemical reaction :7-methylguanosine 5'-triphospho-5'-polyribonucleotide + H2O \rightleftharpoons 7-methylguanosine 5'-phosphate + 5'-diphospho-polyribonucleotide Thus, the two substrates of this enzyme are 7-methylguanosine 5'-triphospho-5'-polynucleotide and H2O, whereas its two products are 7-methylguanosine 5'-phosphate and 5'-diphospho-polyribonucleotide. This enzyme belongs to the family of hydrolases, specifically those acting on acid anhydrides in phosphorus-containing anhydrides. The systematic name of this enzyme class is 7-methylguanosine-5'-triphospho-5'-polynucleotide 7-methylguanosine-5'-phosphohydrolase. Another name in common use is decapase because this enzyme removes the N7-methylguanosine 5-phosphate cap from an mRNA. The process of mRNA decapping controls eukaryotic mRNA degradation. This is the enzyme involved in the processing of amphetamines of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzymology
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphetamines
Substituted amphetamines, or simply amphetamines, are a chemical class, class of compounds based upon the amphetamine structure; it includes all derivative (chemistry), derivative compounds which are formed by replacing, or substitution reaction, substituting, one or more hydrogen atoms in the amphetamine core structure with substituents. The compounds in this class span a variety of pharmacological subclasses, including stimulants, Empathogen-entactogen, empathogens, and hallucinogens, among others. Examples of substituted amphetamines are amphetamine (itself), methamphetamine, ephedrine, cathinone, phentermine, mephentermine, tranylcypromine, bupropion, methoxyphenamine, selegiline, amfepramone, amfepramone (diethylpropion), pyrovalerone, MDMA (ecstasy), and 2,5-dimethoxy-4-methylamphetamine, DOM (STP). Some of amphetamine's substituted Derivative (chemistry), derivatives occur in nature, for example in the leaves of ''Ephedra (genus), Ephedra'' and khat plants. Amphetamine w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messenger RNA Decapping
The process of messenger RNA decapping consists of hydrolysis of the 5' cap structure on the RNA exposing a 5' monophosphate. In eukaryotes, this 5' monophosphate is a substrate for the 5' exonuclease Xrn1 and the mRNA is quickly destroyed. There are many situations which may lead to the removal of the cap, some of which are discussed below. In prokaryotes, the initial mRNA transcript naturally possesses a 5'-triphosphate group after bacterial transcription; the enzyme RppH removes a pyrophosphate molecule from the 5' end, converting the 5'-triphosphate to a 5'-monophosphate, triggering mRNA degradation by ribonucleases. Translation and decay Inside cells, there is a balance between the processes of translation and mRNA decay. Messages which are being actively translated are bound by polysomes and the eukaryotic initiation factors eIF-4E and eIF-4G (in eukaryotes). This blocks access to the cap by the decapping enzyme DCP2 and protects the mRNA molecule. In nutrient-starv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
7-Methylguanosine
7-Methylguanosine (m7G) is a modified purine nucleoside. It is a methylated version of guanosine and when found in human urine, it may be a biomarker of some types of cancer. In the RNAs, 7-methylguanosine have been used to study and examine the reaction evolving methylguanosine. It also participates in the formation of 5'-cap that stabilizes mRNA In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of Protein biosynthesis, synthesizing a protein. mRNA is ... and prevents its degradation by 5' exonucleases. See also * m7G(5')pppN diphosphatase * METTL1 * Messenger RNA decapping * 23S rRNA (guanine2445-N2)-methyltransferase * 16S rRNA (guanine527-N7)-methyltransferase * N1-Methylguanosine (m1G) References External links Metabocard for 7-Methylguanosine (HMDB01107) Human Metabolome Database, University of Alberta Nucleosides Purines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Five-prime Cap
In molecular biology, the five-prime cap (5′ cap) is a specially altered nucleotide on the 5′ end of some primary transcripts such as precursor messenger RNA. This process, known as mRNA capping, is highly regulated and vital in the creation of stable and mature messenger RNA able to undergo translation during protein synthesis. Mitochondrial mRNA and chloroplastic mRNA are not capped. Structure In eukaryotes, the 5′ cap (cap-0), found on the 5′ end of an mRNA molecule, consists of a guanine nucleotide connected to mRNA via an unusual 5′ to 5′ triphosphate linkage. This guanosine is methylated on the 7 position directly after capping ''in vivo'' by a methyltransferase. It is referred to as a 7-methylguanylate cap, abbreviated m7G. The Cap-0 is the base cap structure, however, the first and second transcribed nucleotides can also be 2' O-methylated, leading to the Cap-1 and Cap-2 structures, respectively. This is more common in higher eukaryotes an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Khat
Khat (''Catha edulis''), also known as Bushman's tea, especially in South Africa, is a flowering plant native to eastern and southeastern Africa. It has a history of cultivation originating in the Harar area (present day eastern Ethiopia) and subsequently introduced at different times to countries nearby in East Africa and Southern Arabia, most notably Yemen. Cultivated by farmers, its leaves are sold on the market to be chewed as a recreational stimulant. The world's largest consumers are Eastern Africans, particularly Somalis, and nearby Yemen, with the largest producers/exporters being Ethiopia and Kenya. Khat contains the alkaloid '' cathinone'', a stimulant which causes greater sociability, excitement, mild loss of appetite and mild euphoria. Among communities from the areas where the plant is native, khat-chewing has historical relevance (as a social custom, especially among men) dating back thousands of years, analogous—but slightly different—to the use of coca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mephedrone
Mephedrone, also known as , , and , is a synthetic stimulant drug belonging to the amphetamine and cathinone classes. It is commonly referred to by slang names such as drone, , white magic, meow meow, and bubble. Chemically, it is similar to the cathinone compounds found in the khat plant, native to eastern Africa. Mephedrone is typically found in tablet or crystal form, and users may swallow, snort, or inject it. Its effects are similar to those of MDMA, amphetamines, and cocaine, producing euphoria and increased sociability. Mephedrone is rapidly absorbed, with a half-life of about 2 hours, and is primarily metabolized by CYP2D6 enzymes. Its effects are dose-dependent. Side effects can include cardiovascular changes and anxiety. Mephedrone was first synthesised in 1929 but remained relatively obscure until it was rediscovered around 1999–2000. At that time, it was legal to produce and possess in many countries. By 2000, mephedrone was available for sale on the internet. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathinone
Cathinone (; also known as β-ketoamphetamine) is a monoamine alkaloid found in the shrub ''Catha edulis'' (khat) and is chemically similar to ephedrine, cathine, methcathinone and other amphetamines. It is probably the main contributor to the stimulant effect of ''Catha edulis''. Cathinone differs from many other amphetamines in that it has a ketone functional group. Other phenethylamines that share this structure include the stimulants methcathinone, MDPV, mephedrone and the antidepressant bupropion. History Discovery Khat has been cultivated in the Horn of Africa and Arabian Peninsula region of the world for thousands of years. It is most commonly chewed for the euphoric effect it produces. The active ingredient was first proposed in 1930, when cathine was identified as a predominant alkaloid in the plant. Cathine was thought to be the main active ingredient in khat until the 1960s, when it was found that the amount of cathine in the khat leaves is insufficient to prod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Enzymes
Enzymes are listed here by their classification in the International Union of Biochemistry and Molecular Biology's Enzyme Commission (EC) numbering system: :Oxidoreductases (EC 1) ( Oxidoreductase) * Dehydrogenase * Luciferase * DMSO reductase :EC 1.1 (act on the CH-OH group of donors) * :EC 1.1.1 (with NAD+ or NADP+ as acceptor) ** Alcohol dehydrogenase (NAD) ** Alcohol dehydrogenase (NADP) ** Homoserine dehydrogenase ** Aminopropanol oxidoreductase ** Diacetyl reductase ** Glycerol dehydrogenase ** Propanediol-phosphate dehydrogenase ** glycerol-3-phoshitiendopene dehydrogenase (NAD+) ** D-xylulose reductase ** L-xylulose reductase ** Lactate dehydrogenase ** Malate dehydrogenase ** Isocitrate dehydrogenase ** HMG-CoA reductase * :EC 1.1.2 (with a cytochrome as acceptor) * :EC 1.1.3 (with oxygen as acceptor) ** Glucose oxidase ** L-gulonolactone oxidase ** Thiamine oxidase ** Xanthine oxidase * EC 1.1.4 (with a disulfide as accep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolase
In biochemistry, hydrolases constitute a class of enzymes that commonly function as biochemical catalysts that use water to break a chemical bond: :\ce \quad \xrightarrowtext\quad \ce This typically results in dividing a larger molecule into smaller molecules. Some common examples of hydrolase enzymes are esterases including lipases, phosphatases, glycosidases, peptidases, and nucleosidases. Esterases cleave ester bonds in lipids and phosphatases cleave phosphate groups off molecules. An example of crucial esterase is acetylcholine esterase, which assists in transforming the neuron impulse into the acetate group after the hydrolase breaks the acetylcholine into choline and acetic acid. Acetic acid is an important metabolite in the body and a critical intermediate for other reactions such as glycolysis. Lipases hydrolyze glycerides. Glycosidases cleave sugar molecules off carbohydrates and peptidases hydrolyze peptide bonds. Nucleosidases hydrolyze the bonds of nucleo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Product (chemistry)
Products are the species formed from chemical reactions. During a chemical reaction, reactants are transformed into products after passing through a high energy transition state. This process results in the consumption of the reactants. It can be a spontaneous reaction or mediated by catalysts which lower the energy of the transition state, and by solvents which provide the chemical environment necessary for the reaction to take place. When represented in chemical equations, products are by convention drawn on the right-hand side, even in the case of reversible reactions. The properties of products such as their energies help determine several characteristics of a chemical reaction, such as whether the reaction is exergonic or endergonic. Additionally, the properties of a product can make it easier to extract and purify following a chemical reaction, especially if the product has a different state of matter than the reactants. Spontaneous reaction : R \rightarrow P *W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
