Information on EC 1.7.2.1 - nitrite reductase (NO-forming)

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The expected taxonomic range for this enzyme is: Bacteria, Eukaryota, Archaea

EC NUMBER
COMMENTARY hide
1.7.2.1
-
RECOMMENDED NAME
GeneOntology No.
nitrite reductase (NO-forming)
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
nitric oxide + H2O + ferricytochrome c = nitrite + ferrocytochrome c + 2 H+
show the reaction diagram
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
oxidation
-
-
-
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redox reaction
-
-
-
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reduction
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-
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PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
ammonia oxidation II (anaerobic)
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nitrate reduction I (denitrification)
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nitrate reduction VII (denitrification)
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nitrifier denitrification
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nitrite-dependent anaerobic methane oxidation
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denitrification
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Nitrogen metabolism
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Microbial metabolism in diverse environments
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SYSTEMATIC NAME
IUBMB Comments
nitric-oxide:ferricytochrome-c oxidoreductase
The reaction is catalysed by two types of enzymes, found in the perimplasm of denitrifying bacteria. One type comprises proteins containing multiple copper centres, the other a heme protein, cytochrome cd1. Acceptors include c-type cytochromes such as cytochrome c-550 or cytochrome c-551 from Paracoccus denitrificans or Pseudomonas aeruginosa, and small blue copper proteins such as azurin and pseudoazurin. Cytochrome cd1 also has oxidase and hydroxylamine reductase activities. May also catalyse the reaction of hydroxylamine reductase (EC 1.7.99.1) since this is a well-known activity of cytochrome cd1.
CAS REGISTRY NUMBER
COMMENTARY hide
9027-00-3
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ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
NCIB 11015
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-
Manually annotated by BRENDA team
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-
-
Manually annotated by BRENDA team
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UniProt
Manually annotated by BRENDA team
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SwissProt
Manually annotated by BRENDA team
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SwissProt
Manually annotated by BRENDA team
formerly Aquaspirillum magnetotacticum
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Manually annotated by BRENDA team
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-
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Manually annotated by BRENDA team
wild-type strain MC58, gene nitrite reductase aniA
UniProt
Manually annotated by BRENDA team
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-
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Manually annotated by BRENDA team
DSM 50135
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Manually annotated by BRENDA team
Rhodobacter sphaeroides ATCC 17023 / 2.4.1 / NCIB 8253 / DSM 158
strain 2.4.3
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-
Manually annotated by BRENDA team
Rhodobacter sphaeroides ATCC 17023 / 2.4.1 / NCIB 8253 / DSM 158 ATCC 17023 / 2.4.1 / NCIB 8253 / DSM 158
strain 2.4.3
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-
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
evolution
metabolism
physiological function
additional information
SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
ferrocytochrome c + O2
ferricytochrome c + H2O
show the reaction diagram
ferrocytochrome c-551 + NO2-
NO + ferricytochrome c-551
show the reaction diagram
ferrocytochrome c-551 + O2
ferricytochrome c-551 + H2O
show the reaction diagram
ferrocytochrome c-551 + O2
H2O + ferricytochrome c-551
show the reaction diagram
hydroxylamine + reduced pseudoazurin
NH3 + H2O + oxidized pseudoazurin
show the reaction diagram
-
-
-
-
?
N,N-dimethyl-p-phenylenediamine + oxidized benzyl viologen
?
show the reaction diagram
-
-
-
-
?
NH2OH + reduced cytochrome c550
NH3 + H2O + oxidized cytochrome c550
show the reaction diagram
-
additional electron donor: horse heart cytochrome c
-
?
nitric oxide + H2O + ferricytochrome c
nitrite + ferrocytochrome c + 2 H+
show the reaction diagram
-
-
-
-
?
nitric oxide + H2O + ferricytochrome c551
nitrite + ferrocytochrome c551 + 2 H+
show the reaction diagram
-
-
-
?
nitric oxide + H2O + ferricytochrome c552
nitrite + ferrocytochrome c552 + 2 H+
show the reaction diagram
-
-
-
-
?
nitric oxide + H2O + oxidized phenazine methosulfate
nitrite + reduced phenazine methosulfate + 2 H+
show the reaction diagram
-
phenazine methosulfate can serve as reducing agents and trigger catalytic activity if the assay is performed in relatively long time windows
-
-
?
nitric oxide + H2O + oxidized phenosafranin
nitrite + reduced phenosafranin + 2 H+
show the reaction diagram
-
phenosafranin can serve as reducing agents and trigger catalytic activity if the assay is performed in relatively long time windows
-
-
?
nitrite + dithionite
NO + reduced dithionite
show the reaction diagram
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type 1 copper of the fully loaded protein is reduced both directly by dithionite and indirectly by the type 2 copper site via intramolecular electron transfer
-
-
?
nitrite + electron donor
NO + oxidized electron donor
show the reaction diagram
-
-
-
-
?
nitrite + electron donor
NO + oxidized electron donor + H2O
show the reaction diagram
nitrite + ferrocytochrome b5 + 2 H+
nitric oxide + H2O + ferricytochrome b5
show the reaction diagram
-
-
-
?
nitrite + ferrocytochrome c
nitric oxide + H2O + ferricytochrome c
show the reaction diagram
nitrite + ferrocytochrome c
NO + H2O + ferricytochrome c
show the reaction diagram
nitrite + ferrocytochrome c + 2 H+
nitric oxide + H2O + ferricytochrome c
show the reaction diagram
nitrite + ferrocytochrome c(gamma)
NO + H2O + ferricytochrome c(gamma)
show the reaction diagram
nitrite + ferrocytochrome c2
NO + H2O + ferricytochrome c2
show the reaction diagram
nitrite + ferrocytochrome c550
NO + ferricytochrome c550
show the reaction diagram
-
-
-
-
?
nitrite + ferrocytochrome c550
NO + oxidized ferricytochrome c550
show the reaction diagram
nitrite + H2O + reduced cytochrome cd1
nitric oxide + H+ + cytochrome cd1
show the reaction diagram
-
anaerobic assay conditions
-
-
?
nitrite + H2O + reduced pseudoazurin
nitric oxide + H+ + pseudoazurin
show the reaction diagram
nitrite + methyl viologen
NO + oxidized methyl viologen + H2O
show the reaction diagram
-
-
-
?
nitrite + reduced azurin
NO + H2O + oxidized azurin
show the reaction diagram
nitrite + reduced azurin
NO + oxidized azurin
show the reaction diagram
-
azurin purified from Pseudomonas chlororaphis
-
-
?
nitrite + reduced azurin I
NO + azurin I
show the reaction diagram
-
-
-
?
nitrite + reduced azurin I
NO + oxidized azurin I
show the reaction diagram
nitrite + reduced benzyl viologen
nitric oxide + oxidized benzyl viologen
show the reaction diagram
-
-
-
-
?
nitrite + reduced benzyl viologen
NO + H2O + oxidized benzyl viologen
show the reaction diagram
nitrite + reduced benzyl viologen
NO + oxidized benzyl viologen
show the reaction diagram
nitrite + reduced electron donor
NO + H2O + oxidized electron donor
show the reaction diagram
nitrite + reduced hydroquinone
nitric oxide + H2O + hydroquinone
show the reaction diagram
nitrite + reduced methyl viologen
NO + oxidized methyl viologen
show the reaction diagram
-
random sequential mechanism
-
-
?
nitrite + reduced methyl viologen
NO + oxidized methyl viologen + H2O
show the reaction diagram
nitrite + reduced pseudoazurin
NO + H2O + oxidized pseudoazurin
show the reaction diagram
-
-
-
-
?
nitrite + reduced pseudoazurin
NO + oxidized pseudoazurin
show the reaction diagram
NO2 + reduced methyl viologen
NO + oxidized methylviologen
show the reaction diagram
-
-
-
?
NO2- + ferrocytochrome c
NO + ferricytochrome c
show the reaction diagram
NO2- + morpholine
N-nitrosomorpholine
show the reaction diagram
-
in the presence of diethyldithiocarbamic acid ethylester, nitrosation through the production of NO or NO+-like species
-
?
NO2- + Na2S2O4
NO + Na2S2O3
show the reaction diagram
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pysiological electron donor is unknown, no activity with methyl viologen, phenazine methosulfate or N,N,N',N',-tetramethyl-p-phenylenediamine
-
?
NO2- + reduced ascorbate
NO + oxidized ascorbate
show the reaction diagram
NO2- + reduced azurin
NO + oxidized azurin
show the reaction diagram
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putative physiological electron donor
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?
NO2- + reduced cytochrome c550
NO + oxidized cytochrome c550
show the reaction diagram
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unambiguously identified as physiological electron donor
-
?
NO2- + reduced pseudoazurin
NO + oxidized pseudoazurin
show the reaction diagram
O2 + ferrocytochrome c
H2O + ferricytochrome c
show the reaction diagram
O2 + reduced pseudoazurin
H2O + oxidized pseudoazurin
show the reaction diagram
-
-
-
-
?
O2-. + H+
H2O2 + O2
show the reaction diagram
-
purified enzyme shows superoxide dismutase activity, approx. one-third that of pure superoxide dismutase
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reduced azurin + O2
oxidized azurin + H2O
show the reaction diagram
reduced tetramethyl-4-phenylenediamine + NO2
oxidized tetrametyl-4-phenylenediamine + NO
show the reaction diagram
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no reaction with horse ferrocytochrome c, Neurospora europaea ferrocytochrome c-552, Magnetospirillum magnetotacticum ferrocytochrome c-550 and Pseudomonas aeruginosa cytochrome c-551
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?
reduced tetramethyl-4-phenylenediamine + O2
oxidized tetrametyl-4-phenylenediamine + H2O
show the reaction diagram
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?
additional information
?
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NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
ferrocytochrome c-551 + O2
ferricytochrome c-551 + H2O
show the reaction diagram
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-
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nitric oxide + H2O + ferricytochrome c552
nitrite + ferrocytochrome c552 + 2 H+
show the reaction diagram
-
-
-
-
?
nitrite + electron donor
NO + oxidized electron donor
show the reaction diagram
-
-
-
-
?
nitrite + electron donor
NO + oxidized electron donor + H2O
show the reaction diagram
-
mitochondrial electron carrier cytochrome c can also effectively reduce nitrite to NO. This nitrite reductase activity is highly regulated as it is dependent on pentacoordination of the heme iron in the protein and occurs under anoxic and acidic conditions. In the presence of nitrite, pentacoordinate cytochrome c generates bioavailable NO that is able to inhibit mitochondrial respiration
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-
?
nitrite + ferrocytochrome c
NO + H2O + ferricytochrome c
show the reaction diagram
nitrite + ferrocytochrome c + 2 H+
nitric oxide + H2O + ferricytochrome c
show the reaction diagram
nitrite + ferrocytochrome c2
NO + H2O + ferricytochrome c2
show the reaction diagram
nitrite + ferrocytochrome c550
NO + ferricytochrome c550
show the reaction diagram
-
-
-
-
?
nitrite + reduced azurin I
NO + oxidized azurin I
show the reaction diagram
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coordinate synthesis of azurin I and copper nitrite reductase in Alcaligenes xylosoxidans during denitrification
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-
?
nitrite + reduced electron donor
NO + H2O + oxidized electron donor
show the reaction diagram
nitrite + reduced pseudoazurin
NO + H2O + oxidized pseudoazurin
show the reaction diagram
-
-
-
-
?
nitrite + reduced pseudoazurin
NO + oxidized pseudoazurin
show the reaction diagram
NO2- + ferrocytochrome c
NO + ferricytochrome c
show the reaction diagram
NO2- + reduced cytochrome c550
NO + oxidized cytochrome c550
show the reaction diagram
-
unambiguously identified as physiological electron donor
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?
NO2- + reduced pseudoazurin
NO + oxidized pseudoazurin
show the reaction diagram
-
unambiguously identified as physiological electron donor
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?
reduced azurin + O2
oxidized azurin + H2O
show the reaction diagram
additional information
?
-
COFACTOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
cytochrome
-
cytochrome c
cytochrome cd1
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heme c
heme d
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Heme d1
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
LiCl
-
2 M, enzyme is activated by high salt concentrations
Molybdenum
nitrite reduction is catalyzed by molybdenum in the active site
NaCl
optimum salt concentration: 2 M
NaNO3
-
2 M, enzyme is activated by high salt concentrations
NH4Cl
-
2 M, enzyme is activated by high salt concentrations
Zn
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the recombinant enzyme, expressed in Pseudomonas putida, contains c-heme but no d1-heme. Reconstitution of this protein with Zn-protoporphyrin IX in the place of the d1-heme. Photoexcitation of Zn-NIR is followed by electron transfer from the triplet excited state of the Zn-porphyrin to the oxidized c-haem. Reduction of the d1-heme is associated with a substantial reorganization of the coordination of the metal
Zn2+
-
present on surface of each monomer, crystallization data
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
acetate
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weak, mixed-type inhibition, inhibition mode, overview
azide
-
binding mode, overview
CO
20% residual activity
diethyldithiocarbamate
formate
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weak mixed-type inhibition, inhibition mode, overview
methylhydrazine
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irreversible
NaN3
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1 mM, 60% inhibition
NH2OH
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1 mM, 50% inhibition
nitrate
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weak inhibition, inhibition mode, overview
Nitrous oxide
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binding mode, overview
oxidized cytochrome c
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phenylhydrazine
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irreversible
Tungsten
replacement of molybdenum by tungsten abolishes NO formation
Urea
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4 M, 60% inhibition
additional information
-
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
NapC
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c-type cytochrome with 4 bis-histidinyl coordinated hemes capable of reducing and hence activating oxidized cytochrome cd1 nitrite reductase
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Subtilisin
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species of 48000 Da which contains the d1 but not the c heme
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additional information
-
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.00084 - 0.049
azurin
0.0305 - 0.046
cytochrome c
0.00177 - 0.0075
cytochrome c551
-
0.079
ferricytochrome c551
pH 8.0, 25C
-
0.0018 - 0.0075
Ferrocytochrome c-551
-
0.43 - 2.5
hydroxylamine
0.434 - 2.5
NH2OH
0.00008 - 416
nitrite
0.00147 - 0.8
NO2-
0.027 - 1
O2
0.067 - 0.16
pseudoazurin
-
0.41
reduced methyl viologen
pH and temperature not specified in the publication
additional information
additional information
-
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
7
Abz-VAA
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25C, pH 6.9, recombinant enzyme
1 - 3.2
azurin
1.33
cytochrome c
-
succinylated monomeric enzyme
0.583 - 2.8
cytochrome c551
-
796
ferricytochrome c551
pH 8.0, 25C
-
0.025 - 0.043
Ferrocytochrome c-551
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5
ferrocytochrome c2
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0.1
ferrocytochrome V(gamma)
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-
-
0.08 - 7.7
hydroxylamine
0.08 - 6.4
NH2OH
0.08 - 1478
nitrite
38 - 125
NO
0.08 - 144
NO2-
0.11 - 6.4
O2
additional information
additional information
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kcat/KM VALUE [1/mMs-1]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
10100
ferricytochrome c551
pH 8.0, 25C
-
Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
2
azide
-
recombinant enzyme, pH 6.5, 25C
0.0049
oxidized azurin
-
-
-
0.001 - 0.002
oxidized cytochrome b551
-
-
-
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
0.048
-
nitrite reduction
0.33
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electron donor azurin
2.1
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nitrite reduction, elctron donor methyl viologen
3.32
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reduction of N,N,N',N'-tetramethyl-4-phenyldiamine
10.8
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recombinant enzyme, without activation, enzyme has only type 1 copper centers
22.7
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enzyme is activated 2.5-4.5fold by freezing at -20C for 6 h and subsequent thawing
40
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if reduced nitrite is measured
45.2
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native recombinant enzyme, azurin
80 - 90
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if oxidized benzyl viologen is measured
82
-
mutant N90S, pH 7.1
107
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native recombinant enzyme, dithionite
117
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after storage at -20C for 25 h and thawing in a water bath at 20C
123
-
mutant H254F, pH 7.1
130
-
electron donor benzyl viologen
167.7
-
recombinant enzyme, after activation with CuSO4
168
-
native recombinant enzyme, methyl viologen
240
-
wild-type, pH 7.1
303
pH 6.5, 35C
960
-
in the presence of 2 M NaCl
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
4 - 6.5
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assay at, pH dependence, overview
5.1 - 5.4
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hydroxylamine reduction, electron donor pseudoazurin, pre-reduced cytochrome cd1; NH2OH reduction, electron donor pseudoazurin
5.4
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hydroxylamine reduction, electron donor cytochrome c550, pre-reduced cytochrome cd1; NH2OH reduction, electron donor cytochrome c550
5.6
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reaction with 0.5 mM nitrite and pseudoazurin as electron donor
5.7
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nitrite reduction, electron donor cytochrome c550; nitrite reduction, electron donor cytochrome c550, pre-reduced cytochrome cd1
5.8
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nitrite reduction, electron donor pseudoazurin; nitrite reduction, electron donor pseudoazurin, pre-reduced cytochrome cd1
6.2
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O2 reduction, electron donor cytochrome c550; O2 reduction, electron donor cytochrome c550, pre-reduced cytochrome cd1
6.3
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O2 reduction, electron donor pseudoazurin; O2 reduction, electron donor pseudoazurin, pre-reduced cytochrome cd1
6.5 - 7
pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
4.9 - 6.2
-
pH 4.9: about 55% of maximal ativity, pH 6.2: about 65% of maximal activity, reaction with 0.5 mM nitrite and pseudoazurin as electron donor
5.2 - 6.5
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pH 5.2: about 60% of maximal activity, pH 6.5: about 55% of maximal activity, reaction with 5 mM nitrite and pseudoazurin as electron donor
7.5
3fold decrease in the rate of NO formation compared to pH 6.5; 3fold decrease in the rate of NO formation compared to pH 6.5
additional information
almost no activity at pH 9.0
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
TEMPERATURE RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
60 - 80
60C: about 60% of maximal activity, 80C: about 90% of maximal activity
pI VALUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
5.4 - 6.2
-
isoelectric focusing
9.3
isoelectric focusing
additional information
-
storage at -20C for several months leads to an increase in the number of isoelectrophoretic forms. All preparations have two primary bands, one with a pI of 6.97 and the other of 7.02. Both bands possess significant cytochrome oxidase activity after elution from the gels. When each of the primary bands is eluted and again subject to isoelectric focusing under the same conditions as before, each band interconverts into two bands with pIs of 6.97 and 7.02
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE
-
-
Manually annotated by BRENDA team
-
MLTC-1
Manually annotated by BRENDA team
additional information
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY hide
GeneOntology No.
LITERATURE
SOURCE