The enzyme, found in animals, produces the neurotransmitter?N-acetyl-L-aspartyl-L-glutamate. One isoform also has the activity of EC?6.3.1.17, ¦Â-citrylglutamate synthase [2], while another isoform has the activity of EC?6.3.2.42,?N-acetylaspartylglutamylglutamate synthase [3].