ID 1.5.3.16 DE spermine oxidase. AN SMO. CA H2O + O2 + spermine = 3-aminopropanal + H2O2 + spermidine. CC -!- The enzyme from Arabidopsis thaliana (AtPAO1) oxidizes norspermine to CC norspermidine with high efficiency. CC -!- The mammalian enzyme, encoded by the SMOX gene, is a cytosolic enzyme CC that catalyzes the oxidation of spermine at the exo (three-carbon) CC side of the tertiary amine. CC -!- No activity with spermidine. CC -!- Weak activity with N(1)-acetylspermine. CC -!- Differs in specificity from EC 1.5.3.13, EC 1.5.3.14, EC 1.5.3.15 and CC EC 1.5.3.17. CC -!- Formerly EC 1.5.3.11, EC 1.5.3.n1, EC 1.5.3.n2, EC 1.5.3.n3 and CC EC 1.5.3.n5. DR Q9FNA2, PAO1_ARATH ; Q8H191, PAO4_ARATH ; Q9NWM0, SMOX_HUMAN ; DR Q99K82, SMOX_MOUSE ; //