The enzymatic synthesis of N-acetyl-L-aspartic acid by a water-insoluble preparation of a cat brain acetone powder.

An acetone powder of cat brain catalyzed the synthesis of two radioactive products when incubated with L-aspartate-14C and acetyl coenzyme A. The products were identified as Nacetyl-aspartic acid and citric acid. A water extract of the powder contained the system that produced citrate-14C, while the residue contained the aspartate N-acetyltransferase activity. The soluble system rather than the residue exhibited characteristics previously reported for a soluble aspartate Nacetyltransferase preparation of rat brain; hence, it is suggested that previous investigators were not measuring true L-aspartate N-acetyltransferase activity.