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Fructokinase
Fructokinase (/fruc•to•ki•nase/ ki´nas, also known as D-fructokinase or D-fructose (D-mannose) kinase,DBGET ENZYME: 2.7.1.4 . Retrieved 2007-05-06 is an enzyme () of the , , and kidney cortex. Fructokinase is in a family of enzymes called s, meaning that this enzyme transfers functional groups; it is also considered a |
PFKM
6-phosphofructokinase, muscle type is an enzyme that in humans is encoded by the ''PFKM'' gene on chromosome 12. Three phosphofructokinase isozymes exist in humans: muscle, liver and platelet. These isozymes function as subunits of the mammalian tetramer phosphofructokinase, which catalyzes the phosphorylation of fructose-6-phosphate to fructose-1,6-bisphosphate. Tetramer composition varies depending on tissue type. This gene encodes the muscle-type isozyme. Mutations in this gene have been associated with glycogen storage disease type VII, also known as Tarui disease. Alternatively spliced transcript variants have been described. rovided by RefSeq, Nov 2009ref name="entrez"> Structure Gene This gene is found on chromosome 12. The coding region in ''PFKM'' only shares a 68% similarity with that of the liver-type '' PFKL''. Protein This 85-kDa protein is one of two subunit types that comprise the seven tetrameric PFK isozymes. The muscle isozyme ( PFK-1) is composed sol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphofructokinase
Phosphofructokinase (PFK) is a kinase enzyme that phosphorylates fructose 6-phosphate in glycolysis. Function The enzyme-catalysed transfer of a phosphoryl group from ATP is an important reaction in a wide variety of biological processes. Phosphofructokinase catalyses the phosphorylation of fructose-6-phosphate to fructose-1,6-bisphosphate, a key regulatory step in the glycolytic pathway. It is allosterically inhibited by ATP and allosterically activated by AMP, thus indicating the cell's energetic needs when it undergoes the glycolytic pathway. PFK exists as a homotetramer in bacteria and mammals (where each monomer possesses 2 similar domains) and as an octomer in yeast (where there are 4 alpha- (PFK1) and 4 beta-chains (PFK2), the latter, like the mammalian monomers, possessing 2 similar domains). This protein may use the morpheein model of allosteric regulation. PFK is about 300 amino acids in length, and structural studies of the bacterial enzyme have shown ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PFKL
6-phosphofructokinase, liver type (PFKL) is an enzyme that in humans is encoded by the ''PFKL'' gene on chromosome 21. This gene encodes the liver (L) subunit of an enzyme that catalyzes the conversion of D-fructose 6-phosphate to D- fructose 1,6-bisphosphate, which is a key step in glucose metabolism (glycolysis). This enzyme is a tetramer that may be composed of different subunits encoded by distinct genes in different tissues. Alternative splicing results in multiple transcript variants. rovided by RefSeq, Mar 2014ref name="entrez" /> Structure Gene The PFKL mRNA sequence includes 55 nucleotides at the 5' and 515 nucleotides at the 3' noncoding regions, as well as 2,337 nucleotides in the coding region, encoding 779 amino acids. This coding region only shares a 68% similarity between PFKL and the muscle-type PFKM. Protein This 80-kDa protein is one of three subunit types that comprise the five tetrameric PFK isozymes. The liver PFK (PFK-5) contains solely PFKL, whil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PFKP
Phosphofructokinase, platelet, also known as PFKP is an enzyme which in humans is encoded by the ''PFKP'' gene. Function The PFKP gene encodes the platelet isoform of phosphofructokinase (PFK) (ATP:D-fructose-6-phosphate-1-phosphotransferase, EC 2.7.1.11). PFK catalyzes the irreversible conversion of fructose 6-phosphate to fructose 1,6-bisphosphate and is a key regulatory enzyme in glycolysis Glycolysis is the metabolic pathway that converts glucose () into pyruvate (). The free energy released in this process is used to form the high-energy molecules adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide (NADH .... The PFKP gene, which maps to chromosome 10p, is also expressed in fibroblasts. See also the muscle ( PFKM) and liver ( PFKL) isoforms of phosphofructokinase, which map to chromosomes 12q13 and 21q22, respectively. Full tetrameric phosphofructokinase enzyme expressed in platelets can be composed of subunits P4, P3L, and P2L2. Interactive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinase
In biochemistry, a kinase () is an enzyme that catalyzes the transfer of phosphate groups from high-energy, phosphate-donating molecules to specific substrates. This process is known as phosphorylation, where the high-energy ATP molecule donates a phosphate group to the substrate molecule. This transesterification produces a phosphorylated substrate and ADP. Conversely, it is referred to as dephosphorylation when the phosphorylated substrate donates a phosphate group and ADP gains a phosphate group (producing a dephosphorylated substrate and the high energy molecule of ATP). These two processes, phosphorylation and dephosphorylation, occur four times during glycolysis. Kinases are part of the larger family of phosphotransferases. Kinases should not be confused with phosphorylases, which catalyze the addition of inorganic phosphate groups to an acceptor, nor with phosphatases, which remove phosphate groups (dephosphorylation). The phosphorylation state of a molecule, whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fructose
Fructose, or fruit sugar, is a ketonic simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed by the gut directly into the blood of the portal vein during digestion. The liver then converts both fructose and galactose into glucose, so that dissolved glucose, known as blood sugar, is the only monosaccharide present in circulating blood. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847. The name "fructose" was coined in 1857 by the English chemist William Allen Miller. Pure, dry fructose is a sweet, white, odorless, crystalline solid, and is the most water-soluble of all the sugars. Fructose is found in honey, tree and vine fruits, flowers, berries, and most root vegetables. Commercially, fructose is derived from sugar cane, sugar beets, and maize. High-fructose corn syrup is a mixture of glucose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatic Fructokinase
Hepatic fructokinase (or ketohexokinase) is an enzyme that catalyzes the phosphorylation of fructose to produce fructose-1-phosphate Fructose-1-phosphate is a derivative of fructose. It is generated mainly by hepatic fructokinase but is also generated in smaller amounts in the small intestinal mucosa and proximal epithelium of the renal tubule. It is an important intermediate o .... :ATP + \longrightarrow ADP + : ATP + D-fructose → ADP + D-fructose-1-phosphate Pathology A deficiency is associated with essential fructosuria. References External links * EC 2.7.1 {{2.7-enzyme-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fructose 1-phosphate
Fructose-1-phosphate is a derivative of fructose. It is generated mainly by hepatic fructokinase but is also generated in smaller amounts in the small intestinal mucosa and proximal epithelium of the renal tubule. It is an important intermediate of glucose metabolism. Because fructokinase has a high Vmax fructose entering cells is quickly phosphorylated to fructose 1-phosphate."Marks A. Basic Medical Biochemistry: a clinical approach, 3rd ed. p.540 In this form it is usually accumulated in the liver until it undergoes further conversion by aldolase B (the rate limiting enzyme of fructose metabolism). Aldolase B converts it into glyceraldehyde and dihydroxyacetone phosphate (DHAP). Glyceraldehyde is then phosphorylated by triose kinase to glyceraldehyde 3-phosphate. Metabolism of fructose thus essentially results in intermediates of glycolysis. This means that fructose has the same fate as glucose after it gets metabolised. The final product of glycolysis (pyruvate) may then under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucokinase
Glucokinase () is an enzyme that facilitates phosphorylation of glucose to glucose-6-phosphate. Glucokinase occurs in cells in the liver and pancreas of humans and most other vertebrates. In each of these organs it plays an important role in the regulation of carbohydrate metabolism by acting as a glucose sensor, triggering shifts in metabolism or cell function in response to rising or falling levels of glucose, such as occur after a meal or when fasting. Mutations of the gene for this enzyme can cause unusual forms of diabetes or hypoglycemia. Glucokinase (GK) is a hexokinase isozyme, related homologously to at least three other hexokinases. All of the hexokinases can mediate phosphorylation of glucose to glucose-6-phosphate (G6P), which is the first step of both glycogen synthesis and glycolysis. However, glucokinase is coded by a separate gene and its distinctive kinetic properties allow it to serve a different set of functions. Glucokinase has a lower affinity for g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosine Triphosphate
Adenosine triphosphate (ATP) is an organic compound that provides energy to drive many processes in living cells, such as muscle contraction, nerve impulse propagation, condensate dissolution, and chemical synthesis. Found in all known forms of life, ATP is often referred to as the "molecular unit of currency" of intracellular energy transfer. When consumed in metabolic processes, it converts either to adenosine diphosphate (ADP) or to adenosine monophosphate (AMP). Other processes regenerate ATP. The human body recycles its own body weight equivalent in ATP each day. It is also a precursor to DNA and RNA, and is used as a coenzyme. From the perspective of biochemistry, ATP is classified as a nucleoside triphosphate, which indicates that it consists of three components: a nitrogenous base ( adenine), the sugar ribose, and the triphosphate. Structure ATP consists of an adenine attached by the 9-nitrogen atom to the 1′ carbon atom of a sugar ( ribose), which in tu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liver
The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it is located in the right upper quadrant of the abdomen, below the diaphragm. Its other roles in metabolism include the regulation of glycogen storage, decomposition of red blood cells, and the production of hormones. The liver is an accessory digestive organ that produces bile, an alkaline fluid containing cholesterol and bile acids, which helps the breakdown of fat. The gallbladder, a small pouch that sits just under the liver, stores bile produced by the liver which is later moved to the small intestine to complete digestion. The liver's highly specialized tissue, consisting mostly of hepatocytes, regulates a wide variety of high-volume biochemical reactions, including the synthesis and breakdown of small and complex molecule ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinorhizobium Meliloti
''Ensifer meliloti'' (formerly ''Rhizobium meliloti'' and ''Sinorhizobium meliloti'') are an aerobic, Gram-negative, and diazotrophic species of bacteria. ''S. meliloti'' are motile and possess a cluster of peritrichous flagella. ''S. meliloti'' fix atmospheric nitrogen into ammonia for their legume symbionts, such as alfalfa. ''S. meliloti'' forms a symbiotic relationship with legumes from the genera ''Medicago'', ''Melilotus'' and ''Trigonella'', including the model legume ''Medicago truncatula''. This symbiosis promotes the development of a plant organ, termed a root nodule. Because soil often contains a limited amount of nitrogen for plant use, the symbiotic relationship between ''S. meliloti'' and their legume hosts has agricultural applications. These techniques reduce the need for inorganic nitrogenous fertilizers. Symbiosis Symbiosis between ''S. meliloti'' and its legume hosts begins when the plant secretes an array of betaines and flavonoids into the rhizosphere: 4,4â ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
