1.13.12.16: nitronate monooxygenase
This is an abbreviated version!
For detailed information about nitronate monooxygenase, go to the full flat file.
Word Map on EC 1.13.12.16
-
1.13.12.16
-
nitroalkanes
-
flavin
-
nitroethane
-
neurospora
-
crassa
-
fmn
-
hansenula
-
mrakii
-
flavosemiquinone
-
1-nitropropane
-
denitrification
-
3-nitropropionic
-
ansochromogenes
-
fmn-dependent
-
saturnus
- 1.13.12.16
- nitroalkanes
- flavin
- nitroethane
- neurospora
- crassa
- fmn
- hansenula
- mrakii
-
flavosemiquinone
- 1-nitropropane
-
denitrification
-
3-nitropropionic
- ansochromogenes
-
fmn-dependent
- saturnus
Reaction
Synonyms
2-nitropropane dioxygenase, EC 1.13.11.32, NAO, ncd2, nitroalkane oxidase, nitroalkane-oxidizing enzyme, nitronate monooxygenase, nitropropane dioxygenase, NMO, NMO-Nc, NMO-Ws, nmoA, Npd1, Npd2, Npd3, Npd4, Npd5, Npd6, oxidase, nitroalkane, oxygenase, 2-nitropropane di-, P3N monooxygenase, Pa-NMO, PA4202, protein PA4202, Rv1894c, Sa-NAO
ECTree
1.13.12.16 nitronate monooxygenaseAdvanced search results
results (
results (Substrates Products
Substrates Products on EC 1.13.12.16 - nitronate monooxygenase
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SUBSTRATE 
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
1-hydroxybutyl-2-nitronate + O2
? + HNO2
-
anionic, expression on the basis of the reactivity of propyl-2-nitronate with 2-nitropropane dioxygenase: 31.5
-
-
?
2 Cu((CH3)2CNO2)(PPh3)2 + O2
2 Cu(O2N)(PPh3)2 + 2 propan-2-one
-
using a copper(I) aci-2-nitropropanate complex
-
-
?
2-hydroxybutyl-3-nitronate + O2
? + HNO2
-
anionic, expression on the basis of the reactivity of propyl-2-nitronate with 2-nitropropane dioxygenase: 26.7
-
-
?
2-hydroxypentyl-3-nitronate + O2
? + HNO2
-
anionic, expression on the basis of the reactivity of propyl-2-nitronate with 2-nitropropane dioxygenase: 32.3
-
-
?
2-nitro-1H-indene-1,3(2H)-dione + Cu(0) + N,N,N',N'-tetramethylethylenediamine + O2
1H-indene-1,2,3,-trione + (NO2)CuN,N,N',N'-tetramethylethylenediamine
-
with N,N-dimethylformamid (conversion: 30%) as solvent
-
-
?
2-nitroethanol + O2
glycoaldehyde + HNO2
-
13% of the activity with 2-nitropropane
-
-
?
2-nitroethanol + O2 + H2O
? + HNO2 + H2O2
-
8.4% relative activity (1-nitropropane: 100%)
-
-
?
2-nitropropane + O2 + H2O
acetone + HNO2 + H2O2
-
96.9% relative activity (1-nitropropane: 100%)
-
-
?
3-nitro-1-butanol + O2 + H2O
? + HNO2 + H2O2
-
15.7% relative activity (1-nitropropane: 100%)
-
-
?
3-nitro-2-butanol + O2 + H2O
? + HNO2 + H2O2
-
6.5% relative activity (1-nitropropane: 100%)
-
-
?
3-nitro-2-pentanol + O2 + H2O
2-hydroxy-pentane-3-one + HNO2 + H2O2
-
116% relative activity (1-nitropropane: 100%)
-
-
?
3-nitropropionate + O2 + H2O
? + HNO2 + H2O2
-
0.5% relative activity (1-nitropropane: 100%)
-
-
?
ethylnitronate + Cu(0) + N,N,N',N'-tetramethylethylenediamine + O2
acetone + (NO2)CuN,N,N',N'-tetramethylethylenediamine
-
with N,N-dimethylformamid (conversion: 60%) and pyridine (conversion: 90%) as solvent
-
-
?
ethylnitronate + O2
acetaldehyde + nitrite + other products
-
-
-
?
nitrocyclohexane + O2 + H2O
cyclohexanone + HNO2 + H2O2
-
99.8% relative activity (1-nitropropane: 100%)
-
-
?
nitroethane + O2
acetaldehyde + HNO2 + 1,1-dinitroethane
-
in contrast with the unambiguous stoichiometry of 2-nitropropane oxidation, the nitroethane oxidation is stoichiometrically complicated; 1,1-dinitroethane and nitrate are formed as minor products
-
-
?
nitroethane + O2
ethylnitronate
-
2-nitropropane dioxygenase utilizes a branched catalytic mechanism with nitroethane as substrate. The branch point occurs at the enzyme-ethylnitronate complex and involves either the release of the nitronate or an oxidative denitrification reaction. The partitioning of the enzyme-nitronate complex results in the formation of multiple products from independent catalytic pathways with nitroethane as substrate for the enzyme. In the nonoxidative pathway, nitroethane is deprotonated by histidine 196 to generate ethylnitronate which is subsequently released from the enzyme as a reaction product. The oxidative denitrification pathway was established in previous studies of the enzyme and involves the oxidation of ethylnitronate by the enzyme bound flavin to generate acetaldehyde and nitrite as product
-
-
r
nitroethane + O2 + H2O
? + HNO2 + H2O2
-
51.8% relative activity (1-nitropropane: 100%)
-
-
?
nitromethane + O2 + H2O
? + HNO2 + H2O2
-
7.3% relative activity (1-nitropropane: 100%)
-
-
?
pentane-1-nitronate + Cu(0) + N,N,N',N'-tetramethylethylenediamine + O2
pentaldehyde + (NO2)CuN,N,N',N'-tetramethylethylenediamine
-
with N,N-dimethylformamid (conversion: 28%) and pyridine (conversion: 21%) as solvent
-
-
?
propyl-2-nitronate + Cu(0) + 1,10-phenanthroline + O2
propan-2-one + ?
-
with methanol (conversion: 42%), MeCN (conversion: 24%), and N,N-dimethylformamid (conversion: 43%)
-
-
?
propyl-2-nitronate + Cu(0) + 2,2'-bipyridine + O2
propan-2-one + ?
-
with methanol (conversion: 44%), MeCN (conversion: 54%), and N,N-dimethylformamid (conversion: 37%)
-
-
?
propyl-2-nitronate + Cu(0) + N,N,N',N'-tetramethylethylenediamine + O2
propan-2-one + (NO2)CuN,N,N',N'-tetramethylethylenediamine
-
with methanol (conversion: 70%), MeCN (conversion: 49%), N,N-dimethylformamid (conversion: 71%), and pyridine (conversion: 67%) as solvent
-
-
?
propyl-2-nitronate + Cu(0) + O2
propan-2-one + ?
-
without ligand and without solvent (conversion: 12%)
-
-
?
propylnitronate + O2
? + HNO2
-
anionic, expression on the basis of the reactivity of propyl-2-nitronate with 2-nitropropane dioxygenase: 57.9
-
-
?
undecan-6-nitronate + Cu(0) + N,N,N',N'-tetramethylethylenediamine + O2
undecan-6-one + (NO2)CuN,N,N',N'-tetramethylethylenediamine
-
with N,N-dimethylformamid (conversion: 66%) and pyridine (conversion: 67%) as solvent
-
-
?
1-nitrobutane + O2
butyraldehyde + HNO2
neutral and anionic form
-
-
?
1-nitrohexane + O2
hexanaldehyde + HNO2
neutral and anionic form
-
-
?
1-nitropentane + O2
? + HNO2
-
3% of the activity with 2-nitropropane
-
-
?
1-nitropentane + O2
pentanaldehyde + HNO2
neutral and anionic form
-
-
?
1-nitropropane + O2
propionaldehyde + HNO2
57.9% of activity with 2-nitropropane
-
-
?
1-nitropropane + O2
propionaldehyde + HNO2
-
23.4% of the activity with 2-nitropropane
-
-
?
1-nitropropane + O2
propionaldehyde + HNO2
57.9% of activity with 2-nitropropane (anionic form)
-
-
?
1-nitropropane + O2
propionaldehyde + HNO2
-
23.4% of the activity with 2-nitropropane
-
-
?
1-nitropropane + O2
propionaldehyde + HNO2
-
-
-
?
1-nitropropane + O2
propionaldehyde + HNO2
-
21% of the activity with 2-nitropropane
-
-
?
1-nitropropane + O2
propionaldehyde + HNO2
neutral and anionic form
-
-
?
2-nitro-1-butanol + O2
1-hydroxy-butane-2-one + HNO2
31.5% of the activity with 2-nitropropane
-
-
?
2-nitro-1-butanol + O2
1-hydroxy-butane-2-one + HNO2
2.7% of the activity with 2-nitropropane
-
-
?
2-nitro-1-butanol + O2
1-hydroxy-butane-2-one + HNO2
2.7% of the activity with 2-nitropropane (anionic form)
-
-
?
2-nitro-1-butanol + O2
1-hydroxy-butane-2-one + HNO2
31.5% of the activity with 2-nitropropane (anionic form)
-
-
?
2-nitro-1-propanol + O2
1-hydroxy-propane-2-one + HNO2
7.7% of activity with 2-nitropropane
-
-
?
2-nitro-1-propanol + O2
1-hydroxy-propane-2-one + HNO2
7.7% of activity with 2-nitropropane (anionic form)
-
-
?
2-nitropropane + O2
acetone + HNO2
-
superoxide as reactive intermediate
-
-
?
2-nitropropane + O2
acetone + HNO2
-
superoxide as reactive intermediate
-
-
?
2-nitropropane + O2
acetone + HNO2
-
-
-
?
3 propionate-3-nitronate + O2
3 malonic semialdehyde + nitrite + 2 nitrate + H2O2
-
-
-
?
3 propionate-3-nitronate + O2
3 malonic semialdehyde + nitrite + 2 nitrate + H2O2
best substrate
-
-
?
3-nitro-2-butanol + O2
3-hydroxy-butane-2-one + HNO2
26.7% of the activity with 2-nitropropane
-
-
?
3-nitro-2-butanol + O2
3-hydroxy-butane-2-one + HNO2
-
13% of the activity with 2-nitropropane
-
-
?
3-nitro-2-butanol + O2
3-hydroxy-butane-2-one + HNO2
-
slight oxidation
-
-
?
3-nitro-2-butanol + O2
3-hydroxy-butane-2-one + HNO2
26.7% of the activity with 2-nitropropane (anionic form)
-
-
?
3-nitro-2-butanol + O2
3-hydroxy-butane-2-one + HNO2
-
14% of the activity with 2-nitropropane
-
-
?
3-nitro-2-pentanol + O2
2-hydroxy-pentane-3-one + HNO2
32.3% of the activity with 2-nitropropane
-
-
?
3-nitro-2-pentanol + O2
2-hydroxy-pentane-3-one + HNO2
-
40.6% of the activity with 2-nitropropane
-
-
?
3-nitro-2-pentanol + O2
2-hydroxy-pentane-3-one + HNO2
32.3% of the activity with 2-nitropropane (anionic form)
-
-
?
3-nitro-2-pentanol + O2
2-hydroxy-pentane-3-one + HNO2
-
20% of the activity with 2-nitropropane
-
-
?
3-nitropropionic acid + O2
?
25.5% of the activity with 2-nitropropane
-
-
?
3-nitropropionic acid + O2
?
-
11.7% of the activity with 2-nitropropane
-
-
?
3-nitropropionic acid + O2
?
25.5% of the activity with 2-nitropropane (anionic form)
-
-
?
3-nitropropionic acid + O2
?
-
12% of the activity with 2-nitropropane
-
-
?
ethylnitronate + O2
acetaldehyde + HNO2
-
anionic, expression on the basis of the reactivity of propyl-2-nitronate with 2-nitropropane dioxygenase: 32.5
-
-
?
ethylnitronate + O2
acetaldehyde + HNO2
neutral and anionic form
-
-
?
ethylnitronate + O2 + FMNH2
acetaldehyde + nitrite + FMN + H2O
-
-
-
-
?
ethylnitronate + O2 + FMNH2
acetaldehyde + nitrite + FMN + H2O
-
-
-
-
?
ethylnitronate + O2 + FMNH2
acetaldehyde + nitrite + FMN + H2O
-
reaction via ethylnitronate radical. Catalytic turnover of NMO with ethylnitronate as substrate occurs through both an oxidative denitrification pathway and a non-oxidative pathway in which the anionic substrate is protonated in the active site of the enzyme to form nitroethane as a reaction product
-
-
?
ethylnitronate + O2 + FMNH2
acetaldehyde + nitrite + FMN + H2O
-
-
-
?
nitrocyclohexane + O2
? + HNO2
-
2% of the activity with 2-nitropropane
-
-
?
nitrocyclohexane + O2
cyclohexanone + HNO2
1.5% of the activity with 2-nitropropane
-
-
?
nitrocyclohexane + O2
cyclohexanone + HNO2
1.5% of the activity with 2-nitropropane (anionic form)
-
-
?
nitroethane + O2
?
-
-
-
?
nitroethane + O2
acetaldehyde + HNO2
4.2% of the activity with 2-nitropropane
-
-
?
nitroethane + O2
acetaldehyde + HNO2
-
88% of the activity with nitroethane
-
?
nitroethane + O2
acetaldehyde + HNO2
-
formation of 1,1-dinitroethane and nitrate as minor products
-
-
?
nitroethane + O2
acetaldehyde + HNO2
4.2% of the activity with 2-nitropropane (anionic form)
-
-
?
nitroethane + O2
acetaldehyde + HNO2
-
88% of the activity with nitroethane
-
-
?
nitroethane + O2
acetaldehyde + HNO2
-
27% of the activity with 2-nitropropane
-
-
?
nitroethane + O2
acetaldehyde + HNO2
-
The kinetic isotope effect on the second-order rate constant for nitronate formation, kcat/Km, decreases from an upper limiting value of 23 at low pH to a lower limiting value of 11 at high pH. The difference in the kinetic isotope effects arises from the branching of an enzyme-ethylnitronate reaction intermediate through oxidative and nonoxidative turnover. This branching is isotope sensitive due to a kinetic isotope effect on nitronate release rather than on flavin reduction. The kinetic isotope effect on ethylnitronate release arises from the deprotonation of histidine 196, which provides electrostatic interactions with the nitronate to keep it bound in the active site for oxidation. The isotope effect on branching results in an inflation of the kinetic isotope observed for the nonoxidative pathway to values that are larger than the intrinsic values associated with C-H bond cleavage
-
-
?
nitroethane + O2
acetaldehyde + nitrite
-
2-nitropropane dioxygenase utilizes a branched catalytic mechanism with nitroethane as substrate. The branch point occurs at the enzyme-ethylnitronate complex and involves either the release of the nitronate or an oxidative denitrification reaction. The partitioning of the enzyme-nitronate complex results in the formation of multiple products from independent catalytic pathways with nitroethane as substrate for the enzyme. In the nonoxidative pathway, nitroethane is deprotonated by histidine 196 to generate ethylnitronate which is subsequently released from the enzyme as a reaction product. The oxidative denitrification pathway was established in previous studies of the enzyme and involves the oxidation of ethylnitronate by the enzyme bound flavin to generate acetaldehyde and nitrite as product
-
-
?
nitroethane + O2
acetaldehyde + nitrite
-
catalytic turnover of NMO with nitroethane as substrate occurs with oxidative and non-oxidative pathways with ethylnitronate formation and release in assays of the enzyme with the neutral substrate. The nonoxidative pathway of the enzyme with nitroethane as substrate also involves the H196-catalyzed deprotonation of the nitroalkane and the release of ethylnitronate as a reaction product
-
-
?
nitromethane + O2
formaldehyde + HNO2
4.2% of the activity with 2-nitropropane activity
-
-
?
nitromethane + O2
formaldehyde + HNO2
4.2% of the activity with 2-nitropropane activity (anionic form)
-
-
?
nitromethane + O2
formaldehyde + HNO2
-
is not a substrate, under anaerobic conditions. The aerobic dialysis of the enzyme treated with nitromethane causes reoxidation of only the Fe2+
-
-
?
propyl-2-nitronate + O2 + FMNH2
? + nitrite + FMN + H2O
-
-
-
-
?
additional information
?
-
anaerobic substrate reduction and kinetic data using a Clark oxygen electrode to measure rates of oxygen consumption indicated that the enzyme is active on a broad range of alkyl nitronates, with a marked preference for unbranched substrates over propyl-2-nitronate. The enzyme utilizes alkyl nitronates for catalysis, but not nitroalkanes
-
-
?
additional information
?
-
-
anaerobic substrate reduction and kinetic data using a Clark oxygen electrode to measure rates of oxygen consumption indicated that the enzyme is active on a broad range of alkyl nitronates, with a marked preference for unbranched substrates over propyl-2-nitronate. The enzyme utilizes alkyl nitronates for catalysis, but not nitroalkanes
-
-
?
additional information
?
-
-
enzyme catalyzes the oxygenative denitrification of anionic nitroalkanes much more effectively than that of the neutral ones
-
-
?
additional information
?
-
enzyme catalyzes the oxygenative denitrification of anionic nitroalkanes much more effectively than that of the neutral ones
-
-
?
additional information
?
-
anaerobic substrate reduction and kinetic data using a Clark oxygen electrode to measure rates of oxygen consumption indicates that the enzyme is active on a broad range of alkyl nitronates, with a marked preference for unbranched substrates over propyl-2-nitronate. The enzyme utilizes alkyl nitronates for catalysis, but not nitroalkanes
-
-
?
additional information
?
-
-
anaerobic substrate reduction and kinetic data using a Clark oxygen electrode to measure rates of oxygen consumption indicates that the enzyme is active on a broad range of alkyl nitronates, with a marked preference for unbranched substrates over propyl-2-nitronate. The enzyme utilizes alkyl nitronates for catalysis, but not nitroalkanes
-
-
?
additional information
?
-
-
kinetic evidence for an anion binding pocket in the active site of nitronate monooxygenase
-
-
?
additional information
?
-
-
no activity, nitromethane is inert to the enzyme. The nitroalkanes are not oxidized under anaerobic conditions
-
-
?
additional information
?
-
-
sodium dithionite also reduces both the enzyme-bound FAD and Fe3+ under anaerobic conditions
-
-
?
additional information
?
-
-
sodium dithionite also reduces both the enzyme-bound FAD and Fe3+ under anaerobic conditions
-
-
?
additional information
?
-
-
only alkyl nitronates are used as substrates in the oxidative denitrification reaction catalyzed by Williopsis saturnus var. mrakii NMO, nitroalkanes are no substrates. The different substrate specificity compared to other NMOs might result from the presence of a His residue in the active site and conformational differences. NMO does not produce and release hydrogen peroxide during turnover with linear alkyl nitronates of various lengths between 2 and 6 carbon atoms or with propyl-2-nitronate. With the exception of propyl-2-nitronate, there is no release of superoxide during turnover of NMO at pH 8.0 and 30°C with linear alkyl nitronates with chain lengths between 2 and 6 carbon atoms
-
-
?
additional information
?
-
-
only alkyl nitronates are used as substrates in the oxidative denitrification reaction catalyzed by Williopsis saturnus var. mrakii NMO, nitroalkanes are no substrates. The different substrate specificity compared to other NMOs might result from the presence of a His residue in the active site and conformational differences. NMO does not produce and release hydrogen peroxide during turnover with linear alkyl nitronates of various lengths between 2 and 6 carbon atoms or with propyl-2-nitronate. With the exception of propyl-2-nitronate, there is no release of superoxide during turnover of NMO at pH 8.0 and 30°C with linear alkyl nitronates with chain lengths between 2 and 6 carbon atoms
-
-
?
additional information
?
-
-
active on primary and secondary nitroalkanes, with a marked preference for unbranched primary nitroalkanes
-
-
?
additional information
?
-
-
anionic forms of nitroalkanes are much better substrates than are neutral forms, enzyme does not act on aromatic compounds
-
-
?
additional information
?
-
the reduced enzyme can reduce the substrate under anaerobically conditions, substrate specificity with nitroalkanes and alkyl nitronates, O2 is delivered from air-saturated buffer in the assay reaction, enzyme catalyzes the 2-step oxidative denitrification of nitroalkanes to their corresponding carbonyl compounds and nitrite
-
-
?
additional information
?
-
-
the reduced enzyme can reduce the substrate under anaerobically conditions, substrate specificity with nitroalkanes and alkyl nitronates, O2 is delivered from air-saturated buffer in the assay reaction, enzyme catalyzes the 2-step oxidative denitrification of nitroalkanes to their corresponding carbonyl compounds and nitrite
-
-
?
additional information
?
-
enzyme is more specific for nitronates than nitroalkanes
-
-
?
additional information
?
-
-
enzyme is more specific for nitronates than nitroalkanes
-
-
?
additional information
?
-
-
2-nitropropane dioxygenase utilizes a branched catalytic mechanism with nitroethane as substrate. The branch point occurs at the enzyme-ethylnitronate complex and involves either the release of the nitronate or an oxidative denitrification reaction. The partitioning of the enzyme-nitronate complex results in the formation of multiple products from independent catalytic pathways with nitroethane as substrate for the enzyme. In the nonoxidative pathway, nitroethane is deprotonated by histidine 196 to generate ethylnitronate which is subsequently released from the enzyme as a reaction product
-
-
?
additional information
?
-
-
anionic forms of nitroalkanes are much better substrates than are neutral forms, enzyme does not act on aromatic compounds. Measuring nitrite production with 20 mM anionic nitro compounds as substrates
-
-
?
additional information
?
-
-
kinetic evidence for an anion binding pocket in the active site of nitronate monooxygenase
-
-
?
additional information
?
-
-
both the neutral and anionic forms of nitroalkanes act as substrates for the oxidative denitrification reaction catalyzed by Neurospora crassa NMO. NMO does not produce and release hydrogen peroxide during turnover with linear alkyl nitronates of various lengths between 2 and 6 carbon atoms or with propyl-2-nitronate. With the exception of propyl-1- and propyl-2-nitronate, there is no release of superoxide during turnover of NMO at pH 8.0 and 30°C with linear alkyl nitronates with chain lengths between 2 and 6 carbon atoms
-
-
?
additional information
?
-
the enzyme can catalyze the oxidation of neutral or anionic nitroalkanes and alkyl nitronates to their corresponding carbonyl and nitro compounds
-
-
-
additional information
?
-
the enzyme can catalyze the oxidation of neutral or anionic nitroalkanes and alkyl nitronates to their corresponding carbonyl and nitro compounds
-
-
-
additional information
?
-
the enzyme is active on propionate-3-nitronate and other alkyl nitronates, but cannot oxidize nitroalkanes, e.g. 3-nitropropionate, nitroethane, 1-nitropropane, 1-nitrobutane, 1-nitropentane, or 2-nitropropane. Anaerobic reduction of the enzyme with propionate-3-nitronate yields a flavosemiquinone
-
-
?
