What is the role of glutamate dehydrogenase?
Glutamate dehydrogenase (GDH) catalyzes the reversible inter-conversion of glutamate to α-ketoglutarate and ammonia. High levels of GDH activity is found in mammalian liver, kidney, brain, and pancreas. In the kidney, GDH function produces ammonia from glutamate to control acidosis.
What are the products of the glutamate dehydrogenase reaction?
Glutamate dehydrogenase (GDH) is a hexameric enzyme that catalyzes the reversible conversion of glutamate to α-ketoglutarate and ammonia while reducing NAD(P)+ to NAD(P)H. It is found in all living organisms serving both catabolic and anabolic reactions.
How is glutamate dehydrogenase Allosterically controlled?
Regulation of glutamate dehydrogenase In microbes, the activity is controlled by the concentration of ammonium and or the like-sized rubidium ion, which binds to an allosteric site on GLDH and changes the Km (Michaelis constant) of the enzyme.
How is glutamate dehydrogenase regulated mammals?
Only in the animal kingdom is this enzyme heavily allosterically regulated by a wide array of metabolites. The major activators are ADP and leucine, while the most important inhibitors include GTP, palmitoyl CoA, and ATP.
Is glutamate dehydrogenase mitochondrial enzyme?
Glutamate dehydrogenase (GDH) is a mitochondrial enzyme that is involved in the metabolism of glutamate to 2-oxoglutarate. The GDH enzyme is found primarily in liver, kidney, and cardiac muscle, with lower levels in brain, skeletal muscle, and leukocytes.
What type of reaction is involved in the conversion of glutamate to α-ketoglutarate?
NAD+ is utilized in the reverse reaction, which involves L-glutamate being converted to alpha ketoglutarate and free ammonia via an oxidative deamination reaction (1).
How is glutamate converted into alpha-ketoglutarate?
Glutamate can be synthesized via multiple routes, with two primary sources of synthesis being alpha-ketoglutarate by the enzyme aminotransferase and glutamine by the enzyme glutaminase. Glutamate is metabolized by the enzyme glutamate dehydrogenase (GDH) back to alpha-ketoglutarate.
Is glutamate dehydrogenase allosterically inhibited by ATP?
Only in the animal kingdom is this enzyme heavily allosterically regulated by a wide array of metabolites. The major activators are ADP and leucine and inhibitors include GTP, palmitoyl CoA, and ATP.
Why is glutamate dehydrogenase activated by ADP?
When the mitochondria are at a high-energy state and rich in triphosphates, GDH is inhibited by GTP and, to a lesser extent, ATP. When the mitochondria are low in energy, the elevated ADP levels activate GDH to catabolize glutamate and feed the Krebs cycle with 2-oxoglutarate.
Is glutamate dehydrogenase is allosteric enzyme?
Glutamate dehydrogenase (GDH) is a homohexameric enzyme that catalyzes the reversible oxidative deamination of L-glutamate to 2-oxoglutarate. Only in the animal kingdom is this enzyme heavily allosterically regulated by a wide array of metabolites.
Do humans have glutamate dehydrogenase?
Glutamate dehydrogenase (GDH) catalyzes the oxidative deamination of glutamate to alpha-ketoglutarate using NAD or NADP as cofactors. In the human, GDH exists in heat-resistant and heat-labile isoforms, encoded by the GLUD1 (housekeeping) and GLUD2 (nerve tissue-specific) genes, respectively.