N-Acetylaspartic Acid Unit Converter

N-Acetylaspartic acid (NAA) is an amino acid derivative and one of the most abundant small molecules in the human brain, second only to glutamate. It is formed by combining aspartate with an acetyl group and is found at high concentrations in neurons.

In blood plasma, NAA is present at much lower concentrations than in brain tissue. Plasma levels are thought to reflect a continuous efflux of NAA from the brain into circulation, though peripheral tissues such as brown fat also contribute. Measuring plasma NAA provides an indirect window into neuronal health and whole-body metabolic status.

NAA is broken down by the enzyme aspartoacylase (ASPA), which releases acetate and aspartate. When this enzyme is absent or deficient, NAA accumulates to very high levels in the brain and blood.

NAA is synthesized primarily in neuronal mitochondria, where the enzyme aspartate N-acetyltransferase (NAT8L) combines aspartate with acetyl-CoA. Brown adipose tissue also produces NAA, while the kidneys and oligodendrocytes are major sites of NAA breakdown.