IUBMB Enzyme Nomenclature


Accepted name: N1-acetylpolyamine oxidase

Reaction: (1) N1-acetylspermidine + O2 + H2O = putrescine + 3-acetamidopropanal + H2O2
(2) N1-acetylspermine + O2 + H2O = spermidine + 3-acetamidopropanal + H2O2

Other name(s): hPAO-1; PAO (ambiguous); mPAO; hPAO; polyamine oxidase (ambiguous)

Systematic name: N1-acetylpolyamine:oxygen oxidoreductase (3-acetamidopropanal-forming)

Comments: 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 [polyamine oxidase (propane-1,3-diamine-forming)], EC [N8-acetylspermidine oxidase (propane-1,3-diamine-forming)], EC (spermine oxidase) and EC (non-specific polyamine oxidase).

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:


1. Vujcic, S., Liang, P., Diegelman, P., Kramer, D.L. and Porter, C.W. Genomic identification and biochemical characterization of the mammalian polyamine oxidase involved in polyamine back-conversion. Biochem. J. 370 (2003) 19-28. [PMID: 12477380]

2. Jarvinen, A., Grigorenko, N., Khomutov, A.R., Hyvonen, M.T., Uimari, A., Vepsalainen, J., Sinervirta, R., Keinanen, T.A., Vujcic, S., Alhonen, L., Porter, C.W. and Janne, J. Metabolic stability of α-methylated polyamine derivatives and their use as substitutes for the natural polyamines. J. Biol. Chem. 280 (2005) 6595-6601. [PMID: 15611107]

3. Wang, Y., Hacker, A., Murray-Stewart, T., Frydman, B., Valasinas, A., Fraser, A.V., Woster, P.M. and Casero, R.A., Jr. Properties of recombinant human N1-acetylpolyamine oxidase (hPAO): potential role in determining drug sensitivity. Cancer Chemother Pharmacol 56 (2005) 83-90. [PMID: 15791459]

4. Wu, T., Yankovskaya, V. and McIntire, W.S. Cloning, sequencing, and heterologous expression of the murine peroxisomal flavoprotein, N1-acetylated polyamine oxidase. J. Biol. Chem. 278 (2003) 20514-20525. [PMID: 12660232]

[EC created 2009]

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