Catalyzes the irreversible transamination of the L-tryptophan metabolite L-kynurenine to form kynurenic acid (KA). As a member of the malate-aspartate shuttle, it has a key role in the intracellular NAD(H) redox balance. Is important for metabolite exchange between mitochondria and cytosol, and for amino acid metabolism. 2-oxoglutarate + L-aspartate = L-glutamate + oxaloacetate 2-oxoglutarate + L-kynurenine = H2O + kynurenate + L-glutamate Homodimer. Morpholino knockdown of the protein results in brain developmental defects. Morphants show a small head and seizure-like electroencephalography spikes. Additional defects include slow circulation, bend body and pericardial edema. In eukaryotes there are cytoplasmic, mitochondrial and chloroplastic isozymes. Belongs to the class-I pyridoxal-phosphate-dependent aminotransferase family.