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Your query returned 3 entries. Printable version
EC | 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) |
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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: |
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EC | 2.5.1.44 | ||||||||
Accepted name: | homospermidine synthase | ||||||||
Reaction: | (1) 2 putrescine = sym-homospermidine + NH3 (2) spermidine + putrescine = sym-homospermidine + propane-1,3-diamine |
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For diagram of reaction, click here | |||||||||
Glossary: | sym-homospermidine = N1-(4-aminobutyl)butane-1,4-diamine putrescine = butane-1,4-diamine |
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Other name(s): | putrescine:putrescine 4-aminobutyltransferase (ammonia-forming) | ||||||||
Systematic name: | putrescine/spermidine:putrescine 4-aminobutyltransferase | ||||||||
Comments: | The reaction of this bacterial enzyme occurs in three steps, with some of the intermediates presumably remaining enzyme-bound: (a) NAD+-dependent dehydrogenation of either putrescine or spermidine, forming 4-iminobutan-1-amine or (E)-(4-aminobutylidene)(3-aminopropyl)amine, respectively, (b) attack by water forming 4-aminobutanal (and releasing ammonia or propane-1,3-diamine, respectively), and (c) condensation of 4-aminobutanal with putrescine, which forms homospermidine and restores NAD+. Differs from the eukaryotic enzyme EC 2.5.1.45, homospermidine synthase (spermidine-specific), which cannot use putrescine as donor of the aminobutyl group. | ||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 76106-84-8 | ||||||||
References: |
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EC | 2.5.1.45 | ||||||||
Accepted name: | homospermidine synthase (spermidine-specific) | ||||||||
Reaction: | spermidine + putrescine = sym-homospermidine + propane-1,3-diamine | ||||||||
For diagram of reaction, click here | |||||||||
Glossary: | sym-homospermidine = N1-(4-aminobutyl)butane-1,4-diamine putrescine = butane-1,4-diamine spermidine = N1-(3-aminopropyl)butane-1,4-diamine |
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Systematic name: | spermidine:putrescine 4-aminobutyltransferase (propane-1,3-diamine-forming) | ||||||||
Comments: | A eukaryotic enzyme found in plants. The reaction occurs in three steps, with some of the intermediates presumably remaining enzyme-bound: (a) NAD+-dependent dehydrogenation of spermidine to 4-iminobutan-1-amine, (b) attack by water forming 4-aminobutanal (and releasing propane-1,3-diamine), and (c) condensation of 4-aminobutanal with purescine, which forms homospermidine and restores NAD+. This enzyme is more specific than EC 2.5.1.44, homospermidine synthase, which is found in bacteria, as it cannot use putrescine as donor of the 4-aminobutyl group. Forms part of the biosynthetic pathway of the poisonous pyrrolizidine alkaloids of the ragworts (Senecio). | ||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc | ||||||||
References: |
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