ExplorEnz: EC 1.4.3.27

Your query returned 1 entry. Printable version

1.4.3.27

Accepted name:

homospermidine oxidase

Reaction:

sym-homospermidine + 2 O₂ + H₂O = 1-formylpyrrolizidine + 2 H₂O₂ + 2 NH₃ (overall reaction)
(1a) sym-homospermidine + O₂ = N-(4-aminobutylpyrrolinium) ion + H₂O₂ + NH₃
(1b) N-(4-aminobutylpyrrolinium) ion + O₂ + H₂O = N-(4-oxobutylpyrrolinium) ion + NH₃ + H₂O₂
(1c) N-(4-oxobutylpyrrolinium) ion = 1-formylpyrrolizidine (spontaneous)

Glossary:

(–)-trachelanthamidine = (1R,7aS)-hexahydro-1H-pyrrolizin-1-ylmethanol

Other name(s):

HSO

Systematic name:

homospermidine:oxygen oxidase (deaminating, cyclizing)

Comments:

The copper-containing enzyme has been isolated from the plant Heliotropium indicum. It is involved in the biosynthesis of the pyrrolizidine alkaloid (–)-trachelanthamidine which acts as a secondary metabolite for the defense against herbivores. The oxidation of sym-homospermidine proceeds in three steps and results in a cyclization.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

Zakaria, M.M., Stegemann, T., Sievert, C., Kruse, L.H., Kaltenegger, E., Girreser, U., Cicek, S.S., Nimtz, M. and Ober, D. Insights into polyamine metabolism: homospermidine is double-oxidized in two discrete steps by a single copper-containing amine oxidase in pyrrolizidine alkaloid biosynthesis. Plant Cell 34 (2022) 2364–2382. [DOI] [PMID: 35212762]

[EC 1.4.3.27 created 2022]