Search results
Results from the WOW.Com Content Network
Since aspartate is an amino acid, an amino radical needs to be added to the oxaloacetate. This is supplied by glutamate, which in the process is transformed into alpha-ketoglutarate by the same enzyme. The second antiporter (AGC1 or AGC2) imports glutamate from the cytosol into the matrix and exports aspartate from the matrix to the cytosol.
The two main systems in humans are the glycerol phosphate shuttle and the malate-aspartate shuttle. The malate/a-ketoglutarate antiporter functions move electrons while the aspartate/glutamate antiporter moves amino groups. This allows the mitochondria to receive the substrates that it needs for its functionality in an efficient manner. [1]
Hydrolysis of the amino group of glutamine yielding glutamate and ammonium. Catalyzing enzyme: glutaminase (EC 3.5.1.2) 2. Glutamate can be excreted or can be further metabolized to α-ketoglutarate. For the conversion of glutamate to α-ketoglutarate three different reactions are possible: Catalyzing enzymes: glutamate dehydrogenase (GlDH), EC ...
EAAT1 is also often called the GLutamate ASpartate Transporter 1 (GLAST-1). EAAT1 is predominantly expressed in the plasma membrane, allowing it to remove glutamate from the extracellular space. [6] It has also been localized in the inner mitochondrial membrane as part of the malate-aspartate shuttle. [7]
Aspartate aminotransferase, mitochondrial is an enzyme that in humans is encoded by the GOT2 gene.Glutamic-oxaloacetic transaminase is a pyridoxal phosphate-dependent enzyme which exists in cytoplasmic and inner-membrane mitochondrial forms, GOT1 and GOT2, respectively.
Oxaloacetic acid + Glutamate ⇌ α-Ketoglutarate + Aspartate (catalyzed by aspartate aminotransferase) When skeletal muscle is at rest (ADP<ATP), the aspartate is no longer needed for the purine nucleotide cycle and can therefore be used with α-ketoglutarate to produce glutamate and oxaloacetic acid (the above reaction reversed).
The products usually are either alanine, aspartate or glutamate, since their corresponding alpha-keto acids are produced through metabolism of fuels. Being a major degradative aminoacid pathway, lysine , proline and threonine are the only three amino acids that do not always undergo transamination and rather use respective dehydrogenase.
CO 2 + glutamate + aspartate + 3 ATP + 2 NAD + + 3 H 2 O → urea + α-ketoglutarate + oxaloacetate + 2 ADP + 2 P i + AMP + PP i + 2 NADH; The two NADH produced can provide energy for the formation of 5 ATP (cytosolic NADH provides 2.5 ATP with the malate-aspartate shuttle in human liver cell), a net production of two high-energy phosphate bond ...