ID 1.2.1.15 DE malonate-semialdehyde dehydrogenase. CA (1) 3-oxopropanoate + H2O + NADP(+) = 2 H(+) + malonate + NADPH. CA (2) 3-oxopropanoate + H2O + NAD(+) = 2 H(+) + malonate + NADH. //