N‐Acetylation of L‐Aspartate in the Nervous System: Differential Distribution of a Specific Enzyme

Abstract: L‐Aspartate N‐acetyltransferase, a nervous system enzyme that mediates the synthesis of N‐acetyl‐L‐aspartic acid, has been characterized. In the presence of acetyl‐CoA, L‐aspartate was acetylated 10‐fold more efficiently than L‐glutamate, and the acetylation of aspartylglutamate was not detectable. Within the nervous system, a 10‐fold variation in the enzyme activity was observed, with the brainstem and spinal cord exhibiting the highest activity (10–15 pmol/min/mg tissue) and retina the lowest detectable activity (1–1.5 pmol/min/mg). No enzyme activity was detected in pituitary, heart, liver, or kidney. The enzyme activity was found to be membrane‐associated and was solubilized by treatment with Triton X‐100.