(S)-2-amino-6-oxohexanoate + H2O + NADP(+) = 2 H(+) + L-2-aminoadipate + NADPH (S)-2-amino-6-oxohexanoate + H2O + NAD(+) = 2 H(+) + L-2-aminoadipate + NADH Optimum pH is 9-10. Homotetramer. Belongs to the aldehyde dehydrogenase family.