Carboxynorspermidine synthase

Carboxynorspermidine synthase (EC 1.5.1.43, carboxynorspermidine dehydrogenase, carboxyspermidine dehydrogenase, CASDH, CANSDH) is an enzyme with systematic name carboxynorspermidine:NADP⁺ oxidoreductase. This enzyme catalyses the following chemical reactions

(1) carboxynorspermidine + H₂O + NADP⁺ ⇌ L-aspartate 4-semialdehyde + propane-1,3-diamine + NADPH + H⁺(2) carboxyspermidine + H₂O + NADP⁺ ⇌ L-aspartate 4-semialdehyde + putrescine + NADPH + H⁺

The reaction takes place in the opposite direction.