Glutamate dehydrogenase 1084263 223369611 2008-07-03T19:50:38Z 169.230.76.4 {{protein |Name= [[GLUD1|glutamate dehydrogenase 1]] |caption= |image= |width= |HGNCid=4335 |Symbol=[[GLUD1]] |AltSymbols=GLUD |EntrezGene=2746 |OMIM=138130 |RefSeq=NM_005271 |UniProt=P00367 |PDB= |ECnumber=1.4.1.3 |Chromosome=10 |Arm=q |Band=21.1 |LocusSupplementaryData=-24.3 }} {{protein |Name=glutamate dehydrogenase 2 |caption= |image= |width= |HGNCid=4336 |Symbol=GLUD2 |AltSymbols=GLUDP1 |EntrezGene=2747 |OMIM=300144 |RefSeq=NM_012084 |UniProt=P49448 |PDB= |ECnumber= |Chromosome=X |Arm=q2 |Band=5 |LocusSupplementaryData= }} '''Glutamate dehydrogenase''' is an [[enzyme]], present in [[mitochondria]] of [[eukaryotes]], as are some of the other enzymes required for [[urea]] synthesis, that converts [[glutamate]] to α-[[Ketoglutaric acid|Ketoglutarate]], and vice versa. The produced ammonia is, however, usually bled off to the [[urea cycle]]. <gallery> Image:Glutaminsäure - Glutamic acid.svg|[[Glutamate]] Image:Alpha-ketoglutaric acid.png |[[Ketoglutaric acid|Ketoglutarate]] </gallery> The enzyme represents a key link between [[catabolic]] and [[metabolic pathways]], and is therefore ubiquitous in eukaryotes. ==Cofactors== [[Nicotinamide adenine dinucleotide|NAD]]<sup>+</sup>(or [[NADP]]<sup>+</sup>) is a [[cofactor]] for the glutamate dehydrogenase reaction, producing α-Ketoglutarate and [[ammonium]] as a byproduct. ==Role in flow of nitrogen== Ammonia incorporation in animals occurs through the actions of glutamate dehydrogenase and [[glutamine synthetase]]. Glutamate plays the central role in [[mammalian]] nitrogen flow, serving as both a nitrogen donor and nitrogen acceptor. ==Regulation of glutamate dehydrogenase== In Humans the activity of glutamate dehydrogenase is controlled through [[ADP-ribose|ADP-ribosylation]], a covalent modification carried out by the gene [[sirt4]]. This regulation is relaxed in response to [[caloric restriction]] and low [[blood glucose]]. Under these circumstances glutamate dehydrogenase activity is raised to increase the amount of α-Ketoglutarate that is produced. The product α-Ketoglutarate can be used to provide energy by being used in the [[citric acid cycle]] to ultimately produce [[adenosine triphosphate|ATP]]. The control of GDH through ADP-ribosylation is particularly important in [[insulin]] producing [[β cells]]. Beta cells secrete insulin in response to an increase in the ATP:[[adenosine diphosphate|ADP]] ratio, and as amino acids are broken down by GDH into α-ketoglutarate, this ratio rises and more insulin is secreted. SIRT4 is necessary to regulate the metabolism of amino acids as a method of controlling insulin secretion and to regulate blood [[glucose]] levels. ==Regulation== [[Allosteric regulation|Allosteric inhibitors]]: *[[Adenosine triphosphate]] (ATP) *[[Guanosine triphosphate]] (GTP) Activators: *[[Adenosine diphosphate]] (ADP) *[[Guanosine diphosphate]] (GDP) ==See also== * [[Anaplerotic reactions]] ==External links== * {{MeshName|Glutamate+dehydrogenase}} {{1.4-enzyme-stub}} {{CH-NH2 oxidoreductases}} {{Mitochondrial enzymes}} {{Citric acid cycle enzymes}} {{Amino acid metabolism enzymes}} [[Category:EC 1.4.1]] [[bg:Глутаматдехидрогеназа]] [[de:Glutamatdehydrogenase]] [[it:Glutammato deidrogenasi (NAD(P)+)]] [[nl:Glutamaat-dehydrogenase]] [[ru:Глютаматдегидрогеназа]] [[zh:谷氨酸脱氢酶]]