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Valencene Synthase
Valencene synthase (EC 4.2.3.73) is an enzyme with systematic name (2''E'',6''E'')-farnesyl-diphosphate diphosphate-lyase (valencene-forming). It is a terpene cyclase enzyme responsible for the biosynthesis of valencene, a sesquiterpene, using farnesyl pyrophosphate as its substrate. The first such enzyme was isolated using orange cDNA. This enzyme catalyses the following chemical reaction : (2''E'',6''E'')-farnesyl diphosphate \rightleftharpoons (+)-valencene Valencene is a sesquiterpene that is an aroma component of citrus fruit and citrus-derived odorants. It is obtained inexpensively from Valencia oranges. Valencene is biosynthesized from farnesyl pyrophosphate (FPP) by the CVS enzyme. It is a ... + diphosphate The recombinant enzyme from '' Vitis vinifera'' forms (+)-valencene and (-)-7-''epi''-α-selinene. References External links * {{Portal bar, Biology, border=no EC 4.2.3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the 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 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 are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Enzymes
This article lists enzymes by their classification in the International Union of Biochemistry and Molecular Biology's Enzyme Commission (EC) numbering system. * List of EC numbers (EC 5) * List of EC numbers (EC 6) :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-phosphate 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 disul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclase
A cyclase is an enzyme, almost always a lyase, that catalyzes a chemical reaction to form a cyclic compound. Important cyclase enzymes include: * Adenylyl cyclase, which forms cyclic AMP from adenosine triphosphate (EC 4.6.1.1) ** ADCY1 ** ADCY2 ** ADCY3 ** ADCY4 ** ADCY5 ** ADCY6 ** ADCY7 ** ADCY8 ** ADCY9 ** ADCY10 * Guanylyl cyclase, which forms cyclic GMP from guanosine triphosphate (EC 4.6.1.2) ** GUCY1A2 ** GUCY1A3 ** GUCY1B3 ** Guanylate cyclase 2C ** Guanylate cyclase 2D ** Guanylate cyclase 2F ** NPR1 ** NPR2 * Protein cyclase, a ligase In biochemistry, a ligase is an enzyme that can catalyze the joining (ligation) of two large molecules by forming a new chemical bond. This is typically via hydrolysis of a small pendant chemical group on one of the larger molecules or the enzym ... enzyme that produces backbone-cyclised proteins by intramolecular transpeptidation {{enzyme index EC 4.6.1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valencene
Valencene is a sesquiterpene that is an aroma component of citrus fruit and citrus-derived odorants. It is obtained inexpensively from Valencia oranges. Valencene is biosynthesized from farnesyl pyrophosphate (FPP) by the CVS enzyme. It is a precursor to nootkatone Nootkatone is a natural organic compound, a sesquiterpenoid, and a ketone that is the most important and expensive aromatic of grapefruit, and which also occurs in other organisms. Previously, nootkatone was thought to be one of the main chemic ..., the main contributor to the aroma and flavor of grapefruit and is often used in insecticides, cleaning, personal care products and cosmetics. References {{Terpenes Sesquiterpenes Decalins Alkene derivatives Cyclohexenes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sesquiterpene
Sesquiterpenes are a class of terpenes that consist of three isoprene units and often have the molecular formula C15H24. Like monoterpenes, sesquiterpenes may be cyclic or contain rings, including many unique combinations. Biochemical modifications such as oxidation or rearrangement produce the related sesquiterpenoids. Sesquiterpenes are found naturally in plants and insects, as semiochemicals, e.g. defensive agents or pheromones. Biosynthesis and examples The reaction of geranyl pyrophosphate with isopentenyl pyrophosphate results in the 15-carbon farnesyl pyrophosphate (FPP), which is an intermediate in the biosynthesis of sesquiterpenes such as farnesene. Cyclic sesquiterpenes are more common than cyclic monoterpenes because of the increased chain length and additional double bond in the sesquiterpene precursors. In addition to common six-membered ring systems such as the ones found in zingiberene and bisacurone, cyclization of one end of the chain to the other end can l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Farnesyl Pyrophosphate
Farnesyl pyrophosphate (FPP), also known as farnesyl diphosphate (FDP), is an intermediate in the biosynthesis of terpenes and terpenoids such as sterols and carotenoids. It is also used in the synthesis of CoQ (part of the electron transport chain), as well as dehydrodolichol diphosphate (a precursor of dolichol, which transports proteins to the ER lumen for ''N''-glycosylation). Biosynthesis Farnesyl pyrophosphate synthase (a prenyl transferase) catalyzes sequential condensation reactions of dimethylallyl pyrophosphate with 2 units of 3-isopentenyl pyrophosphate to form farnesyl pyrophosphate, as is shown in the following two steps: * Dimethylallyl pyrophosphate reacts with 3-isopentenyl pyrophosphate to form geranyl pyrophosphate: * Geranyl pyrophosphate then reacts with another molecule of 3-isopentenyl pyrophosphate to form farnesyl pyrophosphate Pharmacology The above reactions are inhibited by bisphosphonates (used for osteoporosis). Farnesyl pyrophosphate is a sel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orange (fruit)
An orange is a fruit of various citrus species in the family (biology), family Rutaceae (see list of plants known as orange); it primarily refers to Citrus × sinensis, ''Citrus'' × ''sinensis'', which is also called sweet orange, to distinguish it from the related ''Citrus × aurantium'', referred to as bitter orange. The sweet orange reproduces asexually (apomixis through nucellar embryony); varieties of sweet orange arise through mutations. The orange is a Hybrid (biology), hybrid between pomelo (''Citrus maxima'') and Mandarin orange, mandarin (''Citrus reticulata''). The chloroplast genome, and therefore the maternal line, is that of pomelo. The sweet orange has had its full Whole genome sequencing, genome sequenced. The orange originated in a region encompassing Southern China, Northeast India, and Myanmar, and the earliest mention of the sweet orange was in Chinese literature in 314 BC. , orange trees were found to be the most Tillage, cultivated fruit tree in the wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CDNA
In genetics, complementary DNA (cDNA) is DNA synthesized from a single-stranded RNA (e.g., messenger RNA (mRNA) or microRNA (miRNA)) template in a reaction catalyzed by the enzyme reverse transcriptase. cDNA is often used to express a specific protein in a cell that does not normally express that protein (i.e., heterologous expression), or to sequence or quantify mRNA molecules using DNA based methods (qPCR, RNA-seq). cDNA that codes for a specific protein can be transferred to a recipient cell for expression, often bacterial or yeast expression systems. cDNA is also generated to analyze transcriptomic profiles in bulk tissue, single cells, or single nuclei in assays such as microarrays, qPCR, and RNA-seq. cDNA is also produced naturally by retroviruses (such as HIV-1, HIV-2, simian immunodeficiency virus, etc.) and then integrated into the host's genome, where it creates a provirus. The term ''cDNA'' is also used, typically in a bioinformatics context, to refer to an mR ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalysis
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst. Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usually gaseous or liquid) as the reactant, or heterogeneous, whose components are not in the same phase. Enzymes and other biocatalysts are often considered as a third category. Catalysis is ubiquitous in chemical industry of all kinds. Estimates are that 90% of all commercially produced chemical products involve catalysts at some s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Reaction
A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the Atomic nucleus, nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive Chemical element, elements where both electronic and nuclear changes can occur. The substance (or substances) initially involved in a chemical reaction are called reagent, reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more Product (chemistry), products, which usually have properties different from the reactants. Reactions often consist of a sequence o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphosphate
In chemistry, pyrophosphates are phosphorus oxyanions that contain two phosphorus atoms in a P–O–P linkage. A number of pyrophosphate salts exist, such as disodium pyrophosphate (Na2H2P2O7) and tetrasodium pyrophosphate (Na4P2O7), among others. Often pyrophosphates are called diphosphates. The parent pyrophosphates are derived from partial or complete neutralization of pyrophosphoric acid. The pyrophosphate bond is also sometimes referred to as a phosphoanhydride bond, a naming convention which emphasizes the loss of water that occurs when two phosphates form a new P–O–P bond, and which mirrors the nomenclature for anhydrides of carboxylic acids. Pyrophosphates are found in ATP and other nucleotide triphosphates, which are important in biochemistry. The term pyrophosphate is also the name of esters formed by the condensation of a phosphorylated biological compound with inorganic phosphate, as for dimethylallyl pyrophosphate. This bond is also referred to as a high-energ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitis Vinifera
''Vitis vinifera'', the common grape vine, is a species of flowering plant, native to the Mediterranean region, Central Europe, and southwestern Asia, from Morocco and Portugal north to southern Germany and east to northern Iran. There are currently between 5,000 and 10,000 varieties of ''Vitis vinifera'' grapes though only a few are of commercial significance for wine and table grape production. The wild grape is often classified as ''Vitis vinifera'' ''sylvestris'' (in some classifications considered ''Vitis sylvestris''), with ''Vitis vinifera'' ''vinifera'' restricted to cultivated forms. Domesticated vines have hermaphrodite flowers, but ''sylvestris'' is dioecious (male and female flowers on separate plants) and pollination is required for fruit to develop. Grapes can be eaten fresh or dried to produce raisins, sultanas, and currants. Grape leaves are used in the cuisine of many cultures. The fresh grapes can also be processed into juice that is fermented to make wine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
