The enzyme also catalyses the reaction: N1,N12-diacetylspermine + O2 + H2O = N1-acetylspermidine + 3-acetamamidopropanal + H2O2 [1]. No or very weak activity with spermine, or spermidine in absence of aldehydes. In presence of aldehydes the enzyme catalyses the reactions: 1. spermine + O2 + H2O = spermidine + 3-aminopropanal + H2O2, and with weak efficiency 2. spermidine + O2 + H2O = putrescine + 3-aminopropanal + H2O2 [2]. A flavoprotein (FAD). This enzyme, encoded by the PAOX gene, is found in mammalian peroxisomes and oxidizes N1-acetylated polyamines at the exo (three-carbon) side of the secondary amine, forming 3-acetamamidopropanal. Since the products of the reactions are deacetylated polyamines, this process is known as polyamine back-conversion. Differs in specificity from EC 1.5.3.14 (polyamine oxidase (propane-1,3-diamine-forming)), EC 1.5.3.15 (N8-acetylspermidine oxidase (propane-1,3-diamine-forming)), EC 1.5.3.16 (spermine oxidase) and EC 1.5.3.17 (non-specific polyamine oxidase).
