AADAT (aminoadipate aminotransferase) is an enzyme that plays a key role in lysine breakdown within the body. Located mainly in the mitochondria, it participates in the alpha-aminoadipic semialdehyde (α-AASA) pathway, converting α-AASA to alpha-aminoadipate (AAA) — a critical step in lysine degradation. This process helps regulate lysine levels and produces intermediates used in other metabolic pathways.