Metabolic pathway
Transamination
Gathers on glutamate the nitrogen that arrives from every amino acid and then releases it as ammonia inside the mitochondrion. It is the funnel the nitrogen passes through before it becomes urea.
- In
- Aspartate + Alanine + 2 Water + 2 NAD⁺
- Out
- Oxaloacetate + Pyruvate + 2 Ammonia + 2 NADH + 2 Proton
- Location
- Cytosol
Fun facts
- Aspartate aminotransferaseIt is the AST (GOT) of blood tests. It does not measure a liver disease: it measures that cells are breaking open and releasing what should stay inside.
- Glutamate dehydrogenaseFree ammonia is toxic to the brain, so the cell produces it where it can get rid of it immediately. It is no coincidence that this enzyme and the first one of the urea cycle share a compartment.
Reactions
| # | Enzyme | ΔG°′ |
|---|---|---|
| 1 | Aspartate aminotransferaseEC 2.6.1.1Aspartate + α-Ketoglutarate ⇌ Glutamate + Oxaloacetate | — |
| 2 | Alanine aminotransferaseEC 2.6.1.2Alanine + α-Ketoglutarate ⇌ Glutamate + Pyruvate | — |
| 3×2 | Glutamate dehydrogenaseEC 1.4.1.3Glutamate + Water + NAD⁺ ⇌ Ammonia + α-Ketoglutarate + NADH + Proton | — |
0 of 3 reactions with a documented ΔG.
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The data sheet includes the map. The logo goes at the bottom.
Sources
- Nelson, D. L. & Cox, M. M. (2021). Lehninger. Principios de bioquímica, 8.ª ed., ch. 18