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]]