Information on EC 1.6.2.2 - cytochrome-b5 reductase

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The expected taxonomic range for this enzyme is: Eukaryota

EC NUMBER
COMMENTARY
1.6.2.2
-
RECOMMENDED NAME
GeneOntology No.
cytochrome-b5 reductase
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
NADH + 2 ferricytochrome b5 = NAD+ + H+ + 2 ferrocytochrome b5
show the reaction diagram
ordered bi bi mechanism
-
NADH + 2 ferricytochrome b5 = NAD+ + H+ + 2 ferrocytochrome b5
show the reaction diagram
hypothetical mechanism
-
NADH + 2 ferricytochrome b5 = NAD+ + H+ + 2 ferrocytochrome b5
show the reaction diagram
electron-transport chain from NADH to a terminal oxidase desaturase, proposed electron transfer mechanism
-
NADH + 2 ferricytochrome b5 = NAD+ + H+ + 2 ferrocytochrome b5
show the reaction diagram
reaction mechanism, overview
-
NADH + 2 ferricytochrome b5 = NAD+ + H+ + 2 ferrocytochrome b5
show the reaction diagram
Y93 forms contact with the FAD, but neither P92 nor Y93 preceeding the conserved motif RxYTSxxSN coordinating flavin binding are critical for flavin incorporation
-
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
oxidation
-
-
-
-
redox reaction
-
-
-
-
reduction
-
-
-
-
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
Amino sugar and nucleotide sugar metabolism
-
-
SYSTEMATIC NAME
IUBMB Comments
NADH:ferricytochrome-b5 oxidoreductase
A flavoprotein (FAD).
SYNONYMS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
B5R
-
-
-
-
cytochrome b5 reductase
-
-
-
-
dihydronicotinamide adenine dinucleotide-cytochrome b5 reductase
-
-
-
-
NADH-cytochrome b5 reductase
-
-
-
-
NADH-cytochrome-b5 reductase
-
-
-
-
NADH-ferricytochrome b5 oxidoreductase
-
-
-
-
P34/P32
-
-
-
-
P35
-
-
-
-
reduced nicotinamide adeninedinucleotide-cytochrome b5 reductase
-
-
-
-
reductase, cytochrome b5
-
-
-
-
CAS REGISTRY NUMBER
COMMENTARY
9032-25-1
-
ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
turnip
-
-
Manually annotated by BRENDA team
L. cv. Ogosta
-
-
Manually annotated by BRENDA team
deficiency leads to 2 different types of recessive congenital methemoglobinemia, in type 1 the soluble enzyme in erythrocytes is affected, in type 2 both soluble and membrane-bound isoforms are affected
-
-
Manually annotated by BRENDA team
different cancer cell lines
-
-
Manually annotated by BRENDA team
native and recombinant enzyme
-
-
Manually annotated by BRENDA team
patients with recessive hereditary methemoglobinemia due to cytochrome b5 reductase deficiency
SwissProt
Manually annotated by BRENDA team
patients with type I recessive congenital methaemoglobinaemia
-
-
Manually annotated by BRENDA team
sequence of natural mutant gene from a patient with recessive congenital methemoglobinemia; patients with recessive congenital methemoglobinemia
SwissProt
Manually annotated by BRENDA team
strain PTCC 5305
SwissProt
Manually annotated by BRENDA team
Mucor racemosus PTCC 5305
strain PTCC 5305
SwissProt
Manually annotated by BRENDA team
cytochrome b5/cytochrome b5 reductase fusion protein, exists also as a variant where the whole exon 12 is deleted
SwissProt
Manually annotated by BRENDA team
learn-pyrethroid-resistance strain, house fly
-
-
Manually annotated by BRENDA team
akkaraman sheep
-
-
Manually annotated by BRENDA team
sipuncilid worm
-
-
Manually annotated by BRENDA team
L. cv Dobrujanski 7
-
-
Manually annotated by BRENDA team
expressed in Escherichia coli
-
-
Manually annotated by BRENDA team
antibodies against the liver enzyme activate NADH 5-alpha reductase
-
-
Manually annotated by BRENDA team
cytochrome b5/cytochrome b5 reductase fusion protein, exists also as a variant where the whole exon 12 is deleted
SwissProt
Manually annotated by BRENDA team
enzyme is expressed through the use of at least 4 different promotors
-
-
Manually annotated by BRENDA team
recombinant enzyme
-
-
Manually annotated by BRENDA team
grown anaerobically
-
-
Manually annotated by BRENDA team
-
SwissProt
Manually annotated by BRENDA team
-
SwissProt
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
evolution
-
CyB5R is a member of the NAD(P)H-ferredoxin reductase (FNR) enzyme superfamily, phylogenetic analysis
malfunction
-
congenital methemoglobinemia due to deficiency of NADH-cytochrome b5 reductase is an autosomal recessive disorder characterized by life long cyanosis
malfunction
-
autosomal cytochrome b5 reductase gene deficiency manifests with the accumulation of oxidized Fe+3 and recessive congenital methemoglobinemia in humans. Diseases related to CyB5R dysfunctions, overviews
malfunction
-
the progeny of plants heterozygous for the cbr1-2 allele segregate 6% homozygous mutants, while cbr1-3 and cbr1-4 heterozygotes segregate 1:1 heterozygous:wild-type, indicating a gametophyte defect. Homozygous cbr1-2 seeds are deformed and required Suc for successful germination and seedling establishment. Vegetative growth of cbr1-2 plants was relatively normal, and they produced abundant flowers, but very few seeds. The pollen produced in cbr1-2 anthers is viable, but when germinated on cbr1-2 or wild-type stigmas, most of the resulting pollen tubes do not extend into the transmitting tract, resulting in a very low frequency of fertilization, phenotype, overview
metabolism
-
2e- transfer from NADH to the enzyme CyB5R, to FAD, followed by reduction of 2 CyB5 and electron transfer to desaturase, CyP450 or methemoglobin
physiological function
-
cytochrome b5 reductase is responsible for the reduction of methemoglobin back to hemoglobin
physiological function
-
cytochrome b5 reductase encoded by CBR1 is essential for a functional male gametophyte in Arabidopsis thaliana. It provides electrons, via cytochrome b5, for a range of biochemical reactions in cellular metabolism, including for fatty acid desaturation in the endoplasmic reticulum. Cytochrome b5 reductase is not essential during vegetative growth but is required for correct pollen function and seed maturation
physiological function
-
cytochrome b5 reductase is involved in the transfer of reducing equivalents from the physiological electron donor, NADH, via an FAD domain to the small molecules of cytochrome b5. It takes part in many oxidation and reduction reactions, such as the reduction of methemoglobin to hemoglobin
physiological function
-
methemoglobin in rainbow trout erythrocytes can be reduced by NADH-dependent cytochrome b5 reductase, i.e. CB5R, or NADPH-dependent methemoglobin reductase. The nucleated red blood cells of rainbow trout use membrane-bound CB5R to reduce methemoglobin
physiological function
-
the enzyme catalyzes the electron transfer from NADH to cytochrome b5 and participates in fatty acid synthesis, cholesterol synthesis, and xenobiotic oxidation as a member of the electron transport chain on the endoplasmic reticulum. In erythrocytes, the enzyme also participates in the reduction of methemoglobin
metabolism
-
the quantity of methemoglobin is kept in balance by an efficient redox system within erythrocytes involving the enzyme, overview
additional information
-
structure-activity relationship, overview
additional information
-
the NADH-cytochrome b5 reductase is a flavoprotein consisting of NADH and FAD binding domains, that catalyzes electron transfer from the two-electron carrier NADH to the one-electron carrier cytochrome b5
additional information
-
the soluble CyB5R diffraction map reveals two distinct domains: the N-terminal FAD binding domain (from I34 to R143), which contains a binding site for the FAD prosthetic group, and the NADH domain (residues K173 to F301). These domains are separated by a large interdomain cleft (G144-V172) known as a hinge region. The three anti-parallel beta-sheets in the hinge region keep the two lobes in close proximity with the correct conformational orientation. This orientation appears to be critical for electron transfer from NADH to FAD. The FAD domain consists of six anti-parallel beta-sheets and one alpha-helix with the order 5beta/1alpha/1beta. The NADH domain forms a alpha/beta/aalpha structure consisting of five beta-strands and four alpha-helices
SUBSTRATE
PRODUCT                      
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
1,2-dihydro-8-(4-methylpiperazin-1-yl)-4-phenylimidazol[3,2-e]pyrazine 5-oxide + NADH
1,2-dihydro-8-(4-methylpiperazin-1-yl)-4-phenylimidazol[3,2-e]pyrazine + NAD+
show the reaction diagram
-
potential bioreductive drug, trivial name RB90740
-
?
2 ferricyanide + NADH
2 ferrocyanide + NAD+ + H+
show the reaction diagram
-
-
-
-
-
2 ferricyanide + NADH
2 ferrocyanide + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricyanide + NADH
2 ferrocyanide + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricyanide + NADH
2 ferrocyanide + NAD+ + H+
show the reaction diagram
P83686
-
-
-
?
2 ferricyanide + NADH
2 ferrocyanide + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricyanide + NADH
2 ferrocyanide + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricyanide + NADH
2 ferrocyanide + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricyanide + NADH
2 ferrocyanide + NAD+ + H+
show the reaction diagram
P00387
-
-
-
?
2 ferricyanide + NADH
2 ferrocyanide + NAD+ + H+
show the reaction diagram
Mucor racemosus, Mucor racemosus PTCC 5305
A8WEG5
-
-
-
?
2 ferricyanide + NADPH
2 ferrocyanide + NADP+ + H+
show the reaction diagram
-
-
-
-
-
2 ferricyanide + NADPH
2 ferrocyanide + NADP+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
Q6BCY4
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
-
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
P83686
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
-
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
Q3TDX8
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
Q68EJ0
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
P00387
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
Q1HA49
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
Q7L1T6
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
low activity with trypsin-solubilized cytochrome b5
-
-
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
-
-
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
-
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
poor electron acceptors: methylene blue, ferricytochrome c, O2, oxidized glutathione, methemoglobin
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
artificial acceptor: ferricyanide
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
artificial electron acceptor in the presence of menadione: cytochrome c
-
-
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
uses both NADH and NADPH as electron donors, artificial acceptors: ferricyanide, 2,6-dichlophenolindophenol
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
additional electron donors: deamino-NADH, 3-acetylpyridine-NADH
-
-
-
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
no acceptors: ubiquinone-30, menadione, dihydrofolate, lipoamide
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
artificial acceptors: p-benzoquinone, 5-hydroxy-1,4-naphthoquinone, nitroblue-tetrazolium
-
-
-
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
artificial acceptor: ferricyanide, high reactivity with NADPH as electron donor
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
additional acceptor: hemin
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
poor donor: NADPH
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
poor donor: NADPH
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
additional acceptor: methemoglobin-ferrocyanide complex
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
additional acceptor: methemoglobin-ferrocyanide complex
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
additional acceptor: methemerythrin
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
recombinant enzyme, very low activity with NADPH
-
-
-
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
membrane bound form of somatic cells: essential for lipid metabolism
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in desaturation of fatty acids
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in desaturation of fatty acids
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in metabolism of endogenous compounds such as steroids, drugs, carcinogens, environmental pollutants
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
Q8W2K4
enzyme is assumed to be part of an endoplasmic reticulum associated redox chain that oxidizes NADH to provide electrons via cytochrome b5 to endoplasmic reticulum associated fatty acyl desaturase and related hydroxylases as in mammals
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
enzyme complex drives the entire sterol 14-demethylation reaction
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
enzyme participates in methemoglobin reduction in erythrocytes, in other tissues it plays a role in elongation and desaturation of fatty acids, P-450 mediated drug metabolism and cholesterol biosynthesis as part of the microsomal electron transfer system
-
-
-
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
soluble form of erythrocytes: reduction of methemoglobin
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
soluble form of erythrocytes: reduction of methemoglobin
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
Q6BCY4
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
P83686
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics, enzyme defects causes methemoglobinemia type I or type II
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics, enzyme in presence of cytochrome b5 supports activity of CYP2E1
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics, mutations can cause methemoglobinemia type I or II
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics, participates in the regeneration of vitamin E and of ascorbate, maintains antioxidant levels and is therefore involved in the protection of membrane lipids from peroxidation, considered as a constitutive housekeeping enzyme
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
Q3TDX8
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics, removal of reactive oxygen species
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
Q68EJ0
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics, removal of reactive oxygen species
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
recessive congenital methaemoglobinaemia, is caused by NADH-cytochrome b5 reductase deficiency. Two distinct clinical forms, types I and II, are recognized, both characterized by cyanosis from birth. In type II, the cyanosis is accompanied by neurological impairment and reduced life expectancy
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
the electrostatic interactions between the lysyl residues (K42, K126, K163, and K164) in the enzyme and the carboxyl groups (E47, E48, E52, E60, and D64) of cytochrome b5 keep the proteins tightly complexed and are suitable for electron transfer, reaction mechanism, overview, potassium ferricyanide, cytochrome b5, or NADH-2,6-dichlorophenol-indophenol can act as electron acceptors
-
-
?
2 ferricytochrome b5 + NADPH
2 ferrocytochrome b5 + NADP+ + H+
show the reaction diagram
Q1HA49
with NADPH the enzyme shows about 20% of the activity with NADH
-
-
?
2 ferricytochrome c + NADH
2 ferrocytochrome c + NAD+ + H+
show the reaction diagram
-
in the presence of outer membrane cytochrome b
-
?
2 ferricytochrome c + NADH
2 ferrocytochrome c + NAD+ + H+
show the reaction diagram
-
increases in the presence of cytochrome b5
-
-
?
2 ferricytochrome c + NADH
2 ferrocytochrome c + NAD+ + H+
show the reaction diagram
Q9ZPN0
reduces also ferricyanide, isoforms I and II, 16% and 27% of Fe3+-citrate reduction respectively
-
?
2 ferricytochrome c + NADH
2 ferrocytochrome c + NAD+ + H+
show the reaction diagram
Q8W2K4
isoforms I and II, 16% and 27% of Fe3+-citrate reduction respectively
-
?
2 ferricytochrome c + NADH
2 ferrocytochrome c + NAD+ + H+
show the reaction diagram
-
cytochrome b5/cytochrome b5 reductase FAD-domain-fusion protein, NADPH is preferred
-
-
2-[4-iodophenyl]-3-[4-nitrophenyl]-5-[2,4-disulfophenyl]-2H tetrazolium monosodium salt + NADH
?
show the reaction diagram
Q6BCY4
-
-
-
?
5alpha-dihydrotestosterone + acceptor
?
show the reaction diagram
-
-
-
-
r
aquacobalamin + NADH
reduced aquacobalamin + NAD+
show the reaction diagram
-
in the presence of outer membrane cytochrome b, no activity with cyanocobalamin
-
?
benzamidoxime + NADH
?
show the reaction diagram
-
in the presence of cytochrome b5
-
-
?
Cu2+-citrate + NADH
Cu+-citrate + NAD+
show the reaction diagram
Q9ZPN0
reduces also ferricyanide, isoforms I and II, 59 and 47% of Fe3+-citrate reduction respectively
-
?
Cu2+-citrate + NADH
Cu+-citrate + NAD+
show the reaction diagram
Q8W2K4
isoforms I and II, 59 and 47% of Fe3+-citrate reduction respectively
-
?
dapsone hydroxylamine + NADH
?
show the reaction diagram
-
in the presence of cytochrome b5
-
-
?
deoxyhemerythrin + O2
?
show the reaction diagram
-
-
-
-
?
Fe3+-ammonium sulfate + NADH
Fe2+-ammonium sulfate + NAD+
show the reaction diagram
-
strongly elevated by the addition of cytochrome b5
-
?
Fe3+-ATP + NADH
Fe2+-ATP + NAD+
show the reaction diagram
-
reconstituted system containing NADH, cytochrome b5 reductase, cytochrome b5 and microsomal lipids catalyzes lipid peroxidation in the presence of ferric-ATP, ferric-histidine and ferric-ammonium sulfate
-
-
Fe3+-ATP + NADH
Fe2+-ATP + NAD+
show the reaction diagram
-
ferric-EDTA is not reduced
-
?
Fe3+-citrate + NADH
Fe2+-citrate + NAD+
show the reaction diagram
Q9ZPN0
isoforms I and II
-
?
Fe3+-citrate + NADH
Fe2+-citrate + NAD+
show the reaction diagram
Q8W2K4
isoforms I and II
-
?
Fe3+-citrate + NADH
Fe2+-citrate + NAD+
show the reaction diagram
Q9ZPN0
reduces also ferricyanide
-
?
Fe3+-EDTA + NADH
Fe2+-EDTA + NAD+
show the reaction diagram
Q9ZPN0
isoforms I and II
-
?
Fe3+-EDTA + NADH
Fe2+-EDTA + NAD+
show the reaction diagram
Q8W2K4
isoforms I and II
-
?
Fe3+-EDTA + NADH
Fe2+-EDTA + NAD+
show the reaction diagram
Q9ZPN0
reduces also ferricyanide
-
?
Fe3+-histidine + NADH
Fe2+-histidine + NAD+
show the reaction diagram
-
strongly elevated by the addition of cytochrome b5
-
?
Fe3+-nitrilotriacetate + NADH
Fe2+-nitrilotriacetate + NAD+
show the reaction diagram
-
in the presence of cytochrome b5, iron chelate reduction in descending order: Fe3+-nitrolotriacetate, Fe3+-ADP, Fe3+-diphosphate, Fe3+-citrate
-
?
ferricytochrome b5 + 4-(5-(4-[amino(hydroxyamino)methyl]phenyl)-2-furyl)-N'-hydroxybenzenecarboximidamide
ferrocytochrome b5 + ?
show the reaction diagram
-
metabolite of DB289, an antimicrobial prodrug of furamidine
-
-
?
ferricytochrome b5 + 4-(5-(4-[amino(hydroxyamino)methyl]phenyl)-2-furyl)-N'-methoxybenzenecarboximidamide
ferrocytochrome b5 + ?
show the reaction diagram
-
metabolite of DB289, an antimicrobial prodrug of furamidine
-
-
?
ferricytochrome b5 + N-hydroxy-2-amino-1-methyl-6-phenylimidazol[4,5-b]pyridine
ferrocytochrome b5 + ?
show the reaction diagram
-
arylhydroxylamine carcinogen found in grilled meat
-
-
?
ferricytochrome b5 + N-hydroxy-4-aminobiphenyl
ferrocytochrome b5 + ?
show the reaction diagram
-
arylhydroxylamine carcinogen found in cigarette smoke
-
-
?
lucigenin + NADH
?
show the reaction diagram
Q6BCY4
-
-
-
?
methemerythrin + NADH
deoxymethemerythrin + NAD+
show the reaction diagram
-
-
-
-
methemerythrin + NADH
deoxymethemerythrin + NAD+
show the reaction diagram
-
-
-
?
methemoglobin + NADH
hemoglobin + NAD+
show the reaction diagram
-
provides functional hemoglobin
-
-
?
NADH + methemoglobin
NAD+ + hemoglobin
show the reaction diagram
-
-
-
-
?
sulfamethoxazole hydroxylamine + NADH
?
show the reaction diagram
-
in the presence of cytochrome b5
-
-
?
methemoglobin-ferrocyanide complex + NADH
reduced methemoglobin-ferrocyanide complex + NAD+
show the reaction diagram
-
-
-
?
additional information
?
-
Q5PY86
role of enzyme in fatty acid desaturation and conjugation
-
-
-
additional information
?
-
-
poor activity with the anticancer drug mitomycin C, no activity with anticancer drug idarubicin. The quinone antitumor agents are used in the treatment of several human neoplasms
-
-
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
membrane bound form of somatic cells: essential for lipid metabolism
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in desaturation of fatty acids
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in desaturation of fatty acids
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in metabolism of endogenous compounds such as steroids, drugs, carcinogens, environmental pollutants
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
Q8W2K4
enzyme is assumed to be part of an endoplasmic reticulum associated redox chain that oxidizes NADH to provide electrons via cytochrome b5 to endoplasmic reticulum associated fatty acyl desaturase and related hydroxylases as in mammals
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
enzyme complex drives the entire sterol 14-demethylation reaction
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
enzyme participates in methemoglobin reduction in erythrocytes, in other tissues it plays a role in elongation and desaturation of fatty acids, P-450 mediated drug metabolism and cholesterol biosynthesis as part of the microsomal electron transfer system
-
-
-
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
soluble form of erythrocytes: reduction of methemoglobin
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
soluble form of erythrocytes: reduction of methemoglobin
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
Q6BCY4
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
P83686
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics, enzyme defects causes methemoglobinemia type I or type II
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics, enzyme in presence of cytochrome b5 supports activity of CYP2E1
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics, mutations can cause methemoglobinemia type I or II
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics, participates in the regeneration of vitamin E and of ascorbate, maintains antioxidant levels and is therefore involved in the protection of membrane lipids from peroxidation, considered as a constitutive housekeeping enzyme
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
Q3TDX8
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics, removal of reactive oxygen species
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
Q68EJ0
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics, removal of reactive oxygen species
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
recessive congenital methaemoglobinaemia, is caused by NADH-cytochrome b5 reductase deficiency. Two distinct clinical forms, types I and II, are recognized, both characterized by cyanosis from birth. In type II, the cyanosis is accompanied by neurological impairment and reduced life expectancy
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
show the reaction diagram
-
the electrostatic interactions between the lysyl residues (K42, K126, K163, and K164) in the enzyme and the carboxyl groups (E47, E48, E52, E60, and D64) of cytochrome b5 keep the proteins tightly complexed and are suitable for electron transfer, reaction mechanism, overview
-
-
?
5alpha-dihydrotestosterone + acceptor
?
show the reaction diagram
-
-
-
-
r
benzamidoxime + NADH
?
show the reaction diagram
-
in the presence of cytochrome b5
-
-
?
dapsone hydroxylamine + NADH
?
show the reaction diagram
-
in the presence of cytochrome b5
-
-
?
deoxyhemerythrin + O2
?
show the reaction diagram
-
-
-
-
?
NADH + methemoglobin
NAD+ + hemoglobin
show the reaction diagram
-
-
-
-
?
sulfamethoxazole hydroxylamine + NADH
?
show the reaction diagram
-
in the presence of cytochrome b5
-
-
?
methemoglobin + NADH
hemoglobin + NAD+
show the reaction diagram
-
provides functional hemoglobin
-
-
?
additional information
?
-
Q5PY86
role of enzyme in fatty acid desaturation and conjugation
-
-
-
additional information
?
-
-
poor activity with the anticancer drug mitomycin C, no activity with anticancer drug idarubicin. The quinone antitumor agents are used in the treatment of several human neoplasms
-
-
-
COFACTOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
FAD
-
1 mol FAD per mol of recombinant enzyme
FAD
-
1 mol FAD per mol enzyme
FAD
-
1 mol FAD per mol enzyme
FAD
-
non-covalently bound in a large cleft between the two major domains
FAD
-
non-covalentely bound prosthetic group
FAD
-
tightly bound prosthetic group
FAD
Q3TDX8
-
FAD
-
cytochrome b5 reductase is composed of one FAD and one NADH binding domain linked by a hinge region
FAD
-
calculated results suggest that the electron and/or hydride ion transfer reaction from NADH to FAD can be accelerated in the presence of heme(Fe3+)
FAD
-
flavoprotein, the FAD domain has a large cleft in which the FAD prosthetic group is located. The N-terminus of the NADH domain plays a hinge-connecting role between the two domains, the FAD and the NADH domains
FAD
-
redox state of FAD during the b5R catalytic cycle and crystal structures comparion of the fully reduced form and the oxidized form, overview
NADH
-
-
NADH
-
native enzyme shows 3700fold preference for NADH over NADPH
NADH
Q3TDX8
-
NADH
-
marked preference for NADH versus NADPH
NADH
Q5PY86
strict specificity for NADH; strict specificity for NADH
NADH
-
preferred electron donor for CyB5R, a D239T mutation will change this preference to one for NADPH. The NADH domain provides a suitable position for the NADH coenzyme. The N-terminus of the NADH domain plays a hinge-connecting role between the two domains, the FAD and the NADH domains
NADH
-
dependent on
NADPH
-
7-9% of NADH activity
NADPH
-
1/300 of NADH linked activity
NADPH
-
preferred cofactor for some engineered enzymes
NADPH
-
marked preference for NADH versus NADPH
NADPH
-
-
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
Ca2+
-
2 mM, 23fold activation
Mg2+
-
half maximal activation at 1 mM
additional information
-
rate of reduction depends on ionic strength
additional information
-
rate of reduction depends on ionic strength
additional information
-
rate of reduction depends on ionic strength
additional information
-
enzyme does not contain appreciable amounts of iron, copper, manganes, silver, mercury, lead, zinc, cobalt or nickel
additional information
-
-
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
(+)-catechin
-
-
(+)-taxifolin
-
-
(-)-epicatechin
-
-
1,10-phenanthroline
-
-
2,2'-dipyridyl
-
-
5'-(p-fluorosulfonylbenzoyl)-adenosine
-
-
5-propyl-2-thiouracil
-
25 mM, almost complete inhibition
acetate
-
-
Acrynol
-
-
Acrynol
-
0.1 mM, 75% inhibition
Acrynol
-
0.1 mM, 88% inhibition
adenine nucleotides
-
-
adenine nucleotides
-
-
ADP
-
5 mM, 66% inhibition
apigenin
-
-
Atebrin
-
-
Atebrin
-
1 mM, complete inhibition
Atebrin
-
0.5 mM, complete inhibition
Atebrin
-
0.1 mM, 44% inhibition
benzyl alcohol
-
100 mM, 52% inhibition, reversible, may be due to changes in membrane fluidity
Br-
-
competitive vs. cytochrome b5, reversible by dilution
CaCl2
-
8 mM, 50% inhibition, competitive vs. cytochrome b5
citrate
-
-
Cl-
-
competitive vs. cytochrome b5, reversible by dilution
dicoumarol
-
-
dicoumarol
-
0.3 mM, 57% inhibition
F-
-
competitive vs. cytochrome b5, reversible by dilution
Hemin
-
-
I-
-
competitive vs cytochrome b5, reversible by dilution
Inositol hexaphosphate
-
-
iodoacetamide
-
1 mM, complete inhibition
iodoacetic acid
-
5 mM, complete inhibition
K+ high ionic strength
-
reduction of cytochrome b5 or dichlorphenolindophenol
-
K+ high ionic strength
-
-
-
luteolin
-
-
luteolin-7-O-glucoside
-
-
Mepacrin
-
-
morin
-
-
myricetin
-
-
myricetin
-
noncompetitive versus NADH, non-linear relationship indicating non-Michaelis-Menten kinetic binding with respect to cytochrome b5
N-ethylmaleimide
-
-
N-ethylmaleimide
-
10 mM, 89% inhibition
N-ethylmaleimide
-
8 mM, 70% inhibition
N-ethylmaleimide
-
1 mM, 90% inhibition
N-ethylmaleimide
-
-
NAD+
-
competitive
NAD+
-
competitive, stronger inhibition of mutant enzymes compared to wild type enzyme
p-chloromercuribenzoate
-
-
p-chloromercuribenzoate
-
0.001 mM, complete inhibition
p-chloromercuribenzoate
-
0.005 mM, complete inhibition
p-chloromercuribenzoate
-
0.001 mM, complete inhibition
p-chloromercuribenzoate
-
-
p-hydroxymercuribenzoate
-
0.1 mM, complete inhibition
p-hydroxymercuribenzoate
-
0.1 mM, almost complete inhibition
para-chloromercuribenzenesulfonate
Q6BCY4
-
Pentachlorophenol
-
-
phosphate
-
competitive inhibition
Phytohemagglutinin
-
-
-
Proflavin
-
0.1 mM, 86% inhibition
Proflavin
-
0.1 mM, 74% inhibition
Proflavin
-
0.1 mM, 98% inhibition
quercetin
-
-
quercitrin
-
-
rutin
-
-
succinate
-
-
taurodeoxycholate
-
-
taurodeoxycholate
-
20 mM, 84% inhibition
Thenoyltrifluoroacetone
-
-
Tris
-
reduction of cytochrome b5
Wheat germ agglutinin
-
-
-
MgCl2
-
78.1 mM, 50% inhibition, competitive vs. cytochrome b5
additional information
-
not inhibited by NAD+ and ferrocyanide
-
additional information
-
high levels of H2O2 inhibit enzyme expression
-
additional information
-
inhibitory potencies of flavonoids on the enzyme, structure-activity relationship, overview. No inhibition by naringenin, naringin, and chrysin. Flavonoids containing two hydroxyl groups in ring B and a carbonyl group at C-4 in combination with a double bond between C-2 and C-3 produced a much stronger inhibition, whereas substitution of a hydroxyl group at C-3 is associated with a less inhibitory effect
-
additional information
-
species-specific sensitivity to methemoglobin induction, in vitro induction of methemoglobin by 1 mM NaNO2, overview
-
additional information
-
enzyme inhibition by dietary flavonoids: inhibitor structure-activity analysis, overview. No inhibition by morin, apigenin, (+)-catechin, (-)-epicatechin, naringenin and naringin
-
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
9-Amino-1,2,3,4-tetrahydroacridine
-
activation
Detergents
-
e.g. Triton X-100, activation
Detergents
-
e.g. Triton X-100, activation
spermine
-
activation
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.83
2,6-dichlorophenolindophenol
-
-
0.0419
aquacobalamin
-
-
0.63
benzamidoxime
-
pH 7.4
0.000007
cytochrome b5
-
-
-
0.000088
cytochrome b5
-
-
-
0.0008
cytochrome b5
-
yeast cytochrome b5
-
0.00114
cytochrome b5
-
-
-
0.00148
cytochrome b5
-
S99A mutant enzyme
-
0.0015
cytochrome b5
-
calf cytochrome b5
-
0.0025
cytochrome b5
-
G273 mutant enzyme
-
0.0028
cytochrome b5
-
-
-
0.003
cytochrome b5
-
K110Q mutant enzyme
-
0.0031
cytochrome b5
-
H49K mutant enzyme
-
0.004
cytochrome b5
-
K110E mutant enzyme
-
0.005
cytochrome b5
-
Y65A mutant enzyme
-
0.0053
cytochrome b5
-
in the presence of 2 mM Ca2+
-
0.0062
cytochrome b5
-
Y65F mutant enzyme
-
0.0066
cytochrome b5
-
recombinant wild-type enzyme
-
0.0069
cytochrome b5
-
K97R mutant enzyme
-
0.00693
cytochrome b5
-
mutant P247L
-
0.0073
cytochrome b5
-
R63K mutant enzyme
-
0.0088
cytochrome b5
-
native enzyme
-
0.0089
cytochrome b5
-
H49A mutant enzyme
-
0.009
cytochrome b5
-
-
-
0.009
cytochrome b5
-
K110A mutant enzyme; K110R mutant enzyme
-
0.0091
cytochrome b5
-
recombinant wild-type enzyme
-
0.0099
cytochrome b5
-
S99V mutant enzyme
-
0.01
cytochrome b5
-
recombinant wild-type enzyme
-
0.0104
cytochrome b5
-
recombinant wild-type enzyme
-
0.011
cytochrome b5
-
recombinant enzyme
-
0.011
cytochrome b5
-
H49Y mutant enzyme
-
0.0118
cytochrome b5
-
S99T mutant enzyme
-
0.012
cytochrome b5
-
K110H mutant enzyme
-
0.013
cytochrome b5
-
-
-
0.0142
cytochrome b5
-
recombinant K110A mutant enzyme
-
0.0143
cytochrome b5
-
-
-
0.015
cytochrome b5
-
-
-
0.0161
cytochrome b5
-
K97A mutant enzyme
-
0.0167
cytochrome b5
-
recombinant K110R mutant enzyme
-
0.017
cytochrome b5
-
DELTAF272 mutant enzyme
-
0.01735
cytochrome b5
-
-
-
0.0185
cytochrome b5
-
R63Q mutant enzyme
-
0.02
cytochrome b5
-
enzyme from erythrocyte membrane
-
0.02
cytochrome b5
-
enzyme from eythrocyte membrane
-
0.02407
cytochrome b5
-
mutant P247A
-
0.0285
cytochrome b5
-
recombinant K110M mutant enzyme
-
0.03 - 0.04
cytochrome b5
-
lysosome- and detergent-solubilized enzyme
-
0.03
cytochrome b5
-
H49E mutant enzyme
-
0.0349
cytochrome b5
-
-
-
0.035
cytochrome b5
-
enzyme from liver microsome membrane, solubilized with Triton X-100
-
0.0362
cytochrome b5
-
L125A mutant enzyme
-
0.04
cytochrome b5
-
enzyme from eythrocyte cytosol
-
0.04148
cytochrome b5
-
mutant P248A
-
0.042
cytochrome b5
-
L41A mutant enzyme
-
0.0421
cytochrome b5
-
R63A mutant enzyme
-
0.045
cytochrome b5
-
enzyme from liver microsome membrane, cathepsin D solubilized
-
0.05238
cytochrome b5
-
mutant P249A
-
0.055
cytochrome b5
-
mutant P249L
-
0.08199
cytochrome b5
-
mutant P248L
-
0.007
cytochrome c
-
cytochrome b5/cytochrome b5 reductase FAD-domain fusion protein
0.36
dapsone hydroxylamine
-
pH 7.4
0.0006
ferricyanide
-
H49K mutant enzyme
0.00104
ferricyanide
-
mutant enzyme P247L, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P247L
0.0016
ferricyanide
-
pH 7.0, 25C,T66V mutant enzyme
0.0022
ferricyanide
-
H49E mutant enzyme
0.0022
ferricyanide
-
pH 7.0, 25C,T66A mutant enzyme
0.0025
ferricyanide
-
native enzyme
0.0025
ferricyanide
-
pH 7.0, 25C, wild type enzyme
0.0026
ferricyanide
-
H49Y mutant enzyme
0.0028
ferricyanide
-
H49A mutant enzyme; recombinant wild-type enzyme
0.0031
ferricyanide
-
pH 7.0, 25C,T66S mutant enzyme
0.0042
ferricyanide
-
-
0.005
ferricyanide
-
K110R mutant enzyme
0.0052
ferricyanide
-
DELTAF272 mutant enzyme; G273 mutant enzyme
0.0058
ferricyanide
-
mutant Y93S, pH 7.0, 25C
0.006
ferricyanide
-
recombinant wild-type enzyme
0.006
ferricyanide
P00387
mutant P275L, 25C, pH 7.0
0.006
ferricyanide
-
wild-type
0.0066
ferricyanide
-
mutant Y93F, pH 7.0, 25C
0.0068
ferricyanide
-
mutant Y93W, pH 7.0, 25C
0.007
ferricyanide
-
recombinant enzyme
0.007
ferricyanide
-
pH 7.0, wild type enzyme
0.007
ferricyanide
P00387
wild-type, 25C, pH 7.0
0.007
ferricyanide
-
mutant G179P, pH 7.0; mutant G179V, pH 7.0
0.007
ferricyanide
-
mutant G75S; mutant V252M
0.0071
ferricyanide
-
wild-type, pH 7.0, 25C
0.00723
ferricyanide
-
; wild type enzyme, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
0.0074
ferricyanide
-
mutant P92A, pH 7.0, 25C
0.0078
ferricyanide
-
mutant P92S, pH 7.0, 25C
0.008
ferricyanide
-
cytochrome b5/cytochrome b5 reductase FAD-domain fusion protein
0.008
ferricyanide
-
L148P mutant enzyme, pH 7.0, 25C; P144L/L148P mutant enzyme, pH 7.0, 25C; P144L mutant enzyme, pH 7.0, 25C; wild type enzyme, pH 7.0, 25C
0.008
ferricyanide
-
pH 7.0, S127P mutant enzyme
0.008
ferricyanide
-
pH 7.0, 25C
0.008
ferricyanide
-
mutant G179A, pH 7.0; mutant G179T, pH 7.0; wild-type, pH 7.0
0.008
ferricyanide
-
mutant P92G, pH 7.0, 25C
0.008
ferricyanide
-
mutant G75S/V252M
0.0083
ferricyanide
-
mutant Y93D, pH 7.0, 25C; mutant Y93H, pH 7.0, 25C
0.0086
ferricyanide
-
mutant Y93A, pH 7.0, 25C
0.01
ferricyanide
-
-
0.01096
ferricyanide
-
mutant enzyme P247A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P247A
0.013
ferricyanide
A8WEG5
-
0.0136
ferricyanide
-
in the presence of 2 mM Ca2+
0.01563
ferricyanide
-
mutant enzyme P248A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P248A
0.01568
ferricyanide
-
mutant enzyme P248L, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P248L
0.017
ferricyanide
-
-
0.0231
ferricyanide
-
-
0.024
ferricyanide
-
-
0.02646
ferricyanide
-
mutant enzyme P249A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P249A
0.03309
ferricyanide
-
mutant enzyme P249L, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P249L
0.0384
ferricyanide
-
-
0.05
ferricyanide
-
K110H mutant enzyme
0.09
ferricyanide
-
-
0.37
ferricyanide
-
K110E mutant enzyme
0.38
ferricyanide
-
K110A mutant enzyme
0.76
ferricyanide
-
K110Q mutant enzyme
3.85
ferricyanide
-
-
4.35
ferricyanide
-
-
0.01
ferricytochome b5
-
L148P mutant enzyme, pH 7.0, 25C
-
0.012
ferricytochome b5
-
P144L mutant enzyme, pH 7.0, 25C
-
0.013
ferricytochome b5
-
P144L/L148P mutant enzyme, pH 7.0, 25C; wild type enzyme, pH 7.0, 25C
-
0.0008
ferricytochrome b5
-
-
0.004
ferricytochrome b5
P00387
wild-type, 25C, pH 7.0
0.01
ferricytochrome b5
-
mutant Y93D, pH 7.0, 25C; mutant Y93H, pH 7.0, 25C
0.011
ferricytochrome b5
-
mutant Y93F, pH 7.0, 25C; mutant Y93W, pH 7.0, 25C
0.012
ferricytochrome b5
P00387
mutant P275L, 25C, pH 7.0
0.012
ferricytochrome b5
-
mutant P92G, pH 7.0, 25C; mutant P92S, pH 7.0, 25C; mutant Y93S, pH 7.0, 25C
0.013
ferricytochrome b5
-
pH 7.0, wild type enzyme
0.013
ferricytochrome b5
-
pH 7.0, 25C,T66S mutant enzyme
0.013
ferricytochrome b5
-
wild-type, pH 7.0, 25C
0.013
ferricytochrome b5
-
mutant V252M; wild-type
0.01353
ferricytochrome b5
-
wild type enzyme, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
0.014
ferricytochrome b5
-
pH 7.0, S127P mutant enzyme
0.014
ferricytochrome b5
-
mutant Y93A, pH 7.0, 25C
0.014
ferricytochrome b5
-
mutant G75S; mutant G75S/V252M
0.014
ferricytochrome b5
Q1HA49
-
0.015
ferricytochrome b5
-
mutant P92A, pH 7.0, 25C
0.02
ferricytochrome b5
-
pH 7.0, 25C, wild type enzyme
0.0207
ferricytochrome b5
-
mutant enzyme P247A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
0.03434
ferricytochrome b5
-
mutant enzyme P248A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
0.04481
ferricytochrome b5
-
mutant enzyme P249A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
0.111
ferricytochrome b5
-
pH 7.0, 25C,T66V mutant enzyme
0.125
ferricytochrome b5
-
pH 7.0, 25C,T66A mutant enzyme
0.001
ferrocytochrome b5
-
mutant G179P, pH 7.0
0.008
ferrocytochrome b5
-
mutant G179A, pH 7.0
0.012
ferrocytochrome b5
-
pH 7.0, 25C
0.013
ferrocytochrome b5
-
wild-type, pH 7.0
0.043
ferrocytochrome b5
-
mutant G179T, pH 7.0
0.107
ferrocytochrome b5
-
mutant G179V, pH 7.0
0.25
N-hydroxy-2-amino-1-methyl-6-phenylimidazol[4,5-b]pyridine
-
pH 7.4
0.22
N-Hydroxy-4-aminobiphenyl
-
pH 7.4
0.00016
NADH
-
enzyme from erythrocyte
0.0003
NADH
-
H49E mutant enzyme
0.0004 - 0.0005
NADH
-
lysosome- and detergent-solubilized enzyme
0.0006 - 0.0007
NADH
-
enzyme from erythrocyte and liver
0.0006
NADH
-
enzyme from erythrocyte membrane
0.0006
NADH
-
recombinant wild-type enzyme
0.00064
NADH
-
G273 mutant enzyme
0.0008
NADH
-
-
0.00084
NADH
-
DELTAF272 mutant enzyme
0.00091
NADH
-
-
0.0011
NADH
-
-
0.0015
NADH
-
recombinant wild-type enzyme
0.0016
NADH
-
native enzyme
0.0019
NADH
-
H49A mutant enzyme
0.0019
NADH
-
S99T mutant enzyme
0.002
NADH
Q1HA49
-
0.0021
NADH
-
R63K mutant enzyme
0.0023
NADH
-
recombinant K110R mutant enzyme
0.0025
NADH
-
-
0.0027
NADH
-
H49Y mutant enzyme
0.0028
NADH
-
pH 7.0, 25C,T66S mutant enzyme; pH 7.0, 25C,T66V mutant enzyme
0.0029
NADH
-
K97R mutant enzyme
0.0029
NADH
-
pH 7.0, 25C,T66A mutant enzyme
0.003
NADH
-
Y65F mutant enzyme
0.003
NADH
-
F251Y mutant enzyme, pH 7.0, 25C
0.003
NADH
-
pH 7.0, wild type enzyme with cytochrome b5 as substrate
0.0031
NADH
-
recombinant wild-type enzyme
0.0031
NADH
-
pH 7.0, 25C, wild type enzyme
0.0038
NADH
-
mutant Y93S, pH 7.0, 25C
0.0042
NADH
-
Y65A mutant enzyme
0.0044
NADH
-
K97A mutant enzyme
0.0048
NADH
-
mutant P92A, pH 7.0, 25C
0.0049
NADH
-
mutant Y93D, pH 7.0, 25C
0.005
NADH
-
D239S/F251Y mutant enzyme, pH 7.0, 25C
0.006
NADH
-
recombinant enzyme
0.006
NADH
-
D239E mutant enzyme, pH 7.0, 25C; wild type enzyme, pH 7.0, 25C
0.006
NADH
-
pH 7.0, wild type enzyme with ferricyanide as substrate
0.006
NADH
P00387
mutant P275L, cosubstrate ferricyanide, 25C, pH 7.0
0.006
NADH
-
wild-type, pH 7.0
0.006
NADH
-
wild-type, pH 7.0, 25C
0.006
NADH
-
wild-type
0.0065
NADH
-
mutant P92G, pH 7.0, 25C
0.0067
NADH
-
mutant Y93F, pH 7.0, 25C
0.007
NADH
-
pH 7.0, 25C
0.0073
NADH
-
mutant Y93A, pH 7.0, 25C
0.0077
NADH
-
mutant P92S, pH 7.0, 25C
0.0088
NADH
-
mutant Y93H, pH 7.0, 25C
0.009
NADH
-
mutant G75S
0.0094
NADH
-
S99V mutant enzyme
0.01
NADH
-
H49K mutant enzyme
0.01097
NADH
-
ferricyanide as electron acceptor; wild type enzyme, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
0.0112
NADH
-
in the presence of 2 mM Ca2+
0.012
NADH
-
F251R mutant enzyme, pH 7.0, 25C
0.0135
NADH
-
mutant enzyme P248L, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P248L, ferricyanide as electron acceptor
0.0144
NADH
-
-
0.0155
NADH
-
mutant enzyme P249L, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P249L, ferricyanide as electron acceptor
0.017
NADH
-
D239S mutant enzyme, pH 7.0, 25C
0.017
NADH
-
mutant G75S/V252M
0.01713
NADH
-
mutant enzyme P247A, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P247A, ferricyanide as electron acceptor
0.0195
NADH
-
-
0.021
NADH
-
R63Q mutant enzyme
0.02407
NADH
-
mutant enzyme P248A, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P248A, ferricyanide as electron acceptor
0.02467
NADH
-
mutant enzyme P247L, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P247L, ferricyanide as electron acceptor
0.025
NADH
-
pH 7.0, S127P mutant enzyme with cytochrome b5 as substrate
0.025
NADH
-
mutant G179A, pH 7.0
0.026
NADH
-
S99A mutant enzyme
0.02928
NADH
-
mutant enzyme P249A, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P249A, ferricyanide as electron acceptor
0.044
NADH
-
-
0.0478
NADH
-
-
0.052
NADH
-
mutant V252M
0.054
NADH
-
mutant Y93W, pH 7.0, 25C
0.055
NADH
-
pH 7.0, S127P mutant enzyme with ferricyanide as substrate
0.104
NADH
-
R63A mutant enzyme
0.119
NADH
-
D239T mutant enzyme, pH 7.0, 25C
0.121
NADH
-
recombinant K110A mutant enzyme
0.224
NADH
-
D239S/F251R mutant enzyme, pH 7.0, 25C
0.512
NADH
-
D239T/F251R mutant enzyme, pH 7.0, 25C
0.595
NADH
-
mutant G179P, pH 7.0
0.662
NADH
-
mutant G179T, pH 7.0
0.672
NADH
-
recombinant K110M mutant enzyme
1.077
NADH
-
mutant G179V, pH 7.0
2.17
NADH
-
-
2.623
NADH
P00387
wild-type, cosubstrate ferricyanide, 25C, pH 7.0
3.32
NADH
-
-
0.001
NADPH
-
cytochrome b5/cytochrome b5 reductase FAD-domain fusion protein
0.009
NADPH
-
D239T mutant enzyme, pH 7.0, 25C
0.022
NADPH
-
D239S/F251R mutant enzyme, pH 7.0, 25C
0.025
NADPH
-
D239S/F251Y mutant enzyme, pH 7.0, 25C
0.044
NADPH
-
D239T/F251R mutant enzyme, pH 7.0, 25C
0.094
NADPH
-
D239E mutant enzyme, pH 7.0, 25C
0.138
NADPH
-
F251R mutant enzyme, pH 7.0, 25C
0.268
NADPH
-
D239S mutant enzyme, pH 7.0, 25C
0.375
NADPH
-
mutant G179V, pH 7.0
0.507
NADPH
-
mutant G179T, pH 7.0
0.617
NADPH
-
F251Y mutant enzyme, pH 7.0, 25C
0.924
NADPH
-
wild type enzyme, pH 7.0, 25C
0.924
NADPH
-
wild-type, pH 7.0
1.36
NADPH
-
mutant G179A, pH 7.0
2.317
NADPH
-
mutant G179P, pH 7.0
2.34
NADPH
-
-
7.69
NADPH
-
-
14
NADPH
-
-
0.36
sulfamethoxazole hydroxylamine
-
pH 7.4
0.025 - 0.089
testosterone
-
depending on phosphate concentration
0.008
methemoglobin-ferrocyanide complex
-
-
-
additional information
additional information
-
detailed analysis of biphasic rate of reduction of cytochrome b5 in membranes. The initial rapid phase is completed within 10 msec and over 90% of cytochrome b5 are reduced in 40 msec. Evaluation of data in terms of two-dimensional random walk model
-
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
50.2
2,6-dichlorophenolindophenol
-
-
1
cytochrome b5
-
K110E mutant enzyme
-
4
cytochrome b5
-
K110Q mutant enzyme
-
21.3
cytochrome b5
-
-
-
27.2
cytochrome b5
-
mutant P247L
-
57
cytochrome b5
-
G273 mutant enzyme
-
90
cytochrome b5
-
K110A mutant enzyme
-
105
cytochrome b5
-
R63Q mutant enzyme
-
107
cytochrome b5
-
Y65A mutant enzyme
-
110
cytochrome b5
-
K110H mutant enzyme
-
121
cytochrome b5
-
R63A mutant enzyme
-
125
cytochrome b5
-
L41A mutant enzyme
-
160
cytochrome b5
-
H49E mutant enzyme
-
165
cytochrome b5
-
S99V mutant enzyme
-
167
cytochrome b5
-
-
-
191
cytochrome b5
-
K97A mutant enzyme
-
200
cytochrome b5
-
K110R mutant enzyme
-
200
cytochrome b5
-
mutant P247A
-
270
cytochrome b5
-
recombinant wild-type enzyme
-
270
cytochrome b5
-
mutant P249L
-
275
cytochrome b5
-
mutant P248L
-
288
cytochrome b5
-
mutant P248A
-
295
cytochrome b5
-
S99A mutant enzyme
-
305
cytochrome b5
-
Y65F mutant enzyme
-
347
cytochrome b5
-
R63K mutant enzyme
-
380
cytochrome b5
-
H49A mutant enzyme
-
415
cytochrome b5
-
K97R mutant enzyme
-
420
cytochrome b5
-
H49K mutant enzyme
-
441
cytochrome b5
-
mutant P249A
-
450
cytochrome b5
-
DELTAF272 mutant enzyme
-
472
cytochrome b5
-
L125A mutant enzyme
-
510
cytochrome b5
-
native enzyme
-
520
cytochrome b5
-
S99T mutant enzyme
-
560
cytochrome b5
-
recombinant wild-type enzyme
-
563
cytochrome b5
-
recombinant K110M mutant enzyme
-
580
cytochrome b5
-
H49Y mutant enzyme
-
661
cytochrome b5
-
recombinant wild-type enzyme
-
742
cytochrome b5
-
recombinant K110A mutant enzyme
-
872
cytochrome b5
-
recombinant wild-type enzyme
-
877
cytochrome b5
-
recombinant K110R mutant enzyme
-
8.3
cytochrome c
-
cytochrome b5/cytochrome b5 reductase FAD-domain fusion protein
12
ferricyanide
-
mutant G179V, pH 7.0
21.7
ferricyanide
-
cytochrome b5/cytochrome b5 reductase FAD-domain fusion protein
30.8
ferricyanide
-
mutant enzyme P247L, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P247L
33
ferricyanide
-
mutant G179T, pH 7.0
40
ferricyanide
-
K110Q mutant enzyme
42
ferricyanide
-
mutant G179P, pH 7.0
76
ferricyanide
-
G273 mutant enzyme
77
ferricyanide
-
pH 7.0, 25C,T66V mutant enzyme
83
ferricyanide
-
mutant Y93D, pH 7.0, 25C; mutant Y93H, pH 7.0, 25C; mutant Y93W, pH 7.0, 25C
98.3
ferricyanide
-
enzyme from liver microsomes, protease solubilized
100
ferricyanide
-
P144L/L148P mutant enzyme, pH 7.0, 25C
110
ferricyanide
-
H49E mutant enzyme
120
ferricyanide
-
K110E mutant enzyme
133
ferricyanide
-
mutant Y93S, pH 7.0, 25C
133
ferricyanide
-
mutant G75S
187
ferricyanide
-
mutant G75S/V252M
200
ferricyanide
-
mutant Y93A, pH 7.0, 25C
270
ferricyanide
-
K110A mutant enzyme
283
ferricyanide
-
P144L mutant enzyme, pH 7.0, 25C
300
ferricyanide
-
L148P mutant enzyme, pH 7.0, 25C
300
ferricyanide
-
pH 7.0, S127P mutant enzyme
307
ferricyanide
-
-
337
ferricyanide
-
; wild type enzyme, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
340
ferricyanide
-
K110H mutant enzyme
357
ferricyanide
-
mutant enzyme P247A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P247A
367
ferricyanide
-
-
399
ferricyanide
-
mutant enzyme P248A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P248A
400
ferricyanide
-
DELTAF272 mutant enzyme
467
ferricyanide
-
mutant P92G, pH 7.0, 25C
470
ferricyanide
-
H49A mutant enzyme
470
ferricyanide
-
K110R mutant enzyme
483
ferricyanide
-
mutant Y93F, pH 7.0, 25C
490
ferricyanide
-
H49K mutant enzyme
500
ferricyanide
-
-
504
ferricyanide
-
mutant enzyme P248L, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P248L
517
ferricyanide
-
mutant P92A, pH 7.0, 25C
559
ferricyanide
-
mutant G179A, pH 7.0
630
ferricyanide
-
native enzyme
633
ferricyanide
-
mutant V252M
667
ferricyanide
-
-
677
ferricyanide
-
enzyme from erythrocyte membrane
684
ferricyanide
-
pH 7.0, 25C,T66A mutant enzyme
700
ferricyanide
-
enzyme from erythrocyte cytosol
727
ferricyanide
-
H49Y mutant enzyme
767
ferricyanide
-
pH 7.0, 25C
800
ferricyanide
-
recombinant wild-type enzyme
800
ferricyanide
-
wild type enzyme, pH 7.0, 25C
800
ferricyanide
-
pH 7.0, wild type enzyme
800
ferricyanide
-
wild-type, pH 7.0
800
ferricyanide
-
wild-type, pH 7.0, 25C
800
ferricyanide
-
wild-type
810
ferricyanide
-
recombinant wild-type enzyme
822
ferricyanide
-
pH 7.0, 25C, wild type enzyme
827
ferricyanide
-
enzyme from liver microsomes, detergent solubilized
838
ferricyanide
-
mutant enzyme P249A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P249A
880
ferricyanide
-
mutant P92S, pH 7.0, 25C
976
ferricyanide
-
pH 7.0, 25C,T66S mutant enzyme
1241
ferricyanide
-
mutant enzyme P249L, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P249L
33
ferricytochome b5
-
P144L/L148P mutant enzyme, pH 7.0, 25C
-
117
ferricytochome b5
-
P144L mutant enzyme, pH 7.0, 25C
-
130
ferricytochome b5
-
L148P mutant enzyme, pH 7.0, 25C
-
417
ferricytochome b5
-
wild type enzyme, pH 7.0, 25C
-
14
ferricytochrome b5
-
mutant Y93D, pH 7.0, 25C
19
ferricytochrome b5
-
mutant Y93W, pH 7.0, 25C
27
ferricytochrome b5
-
mutant Y93H, pH 7.0, 25C
32
ferricytochrome b5
-
mutant Y93S, pH 7.0, 25C
38
ferricytochrome b5
-
pH 7.0, 25C,T66V mutant enzyme
57
ferricytochrome b5
-
mutant Y93A, pH 7.0, 25C
60
ferricytochrome b5
-
mutant G75S
67
ferricytochrome b5
P00387
mutant P275L, 25C, pH 7.0
85
ferricytochrome b5
-
mutant G75S/V252M
106
ferricytochrome b5
-
pH 7.0, S127P mutant enzyme
147
ferricytochrome b5
-
wild type enzyme, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
167
ferricytochrome b5
-
mutant enzyme P247A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
285
ferricytochrome b5
-
mutant V252M
295
ferricytochrome b5
-
mutant Y93F, pH 7.0, 25C
301
ferricytochrome b5
-
mutant enzyme P248A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
314
ferricytochrome b5
-
pH 7.0, 25C,T66A mutant enzyme
315
ferricytochrome b5
-
mutant P92S, pH 7.0, 25C
320
ferricytochrome b5
-
mutant P92A, pH 7.0, 25C
335
ferricytochrome b5
-
mutant P92G, pH 7.0, 25C
360
ferricytochrome b5
-
wild-type
367
ferricytochrome b5
-
pH 7.0, wild type enzyme
400
ferricytochrome b5
-
wild-type, pH 7.0, 25C
540
ferricytochrome b5
-
mutant enzyme P249A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
600
ferricytochrome b5
P00387
wild-type, 25C, pH 7.0
705
ferricytochrome b5
-
pH 7.0, 25C,T66S mutant enzyme
911
ferricytochrome b5
-
pH 7.0, 25C, wild type enzyme
10
ferrocytochrome b5
-
mutant G179P, pH 7.0
17
ferrocytochrome b5
-
mutant G179V, pH 7.0
18
ferrocytochrome b5
-
mutant G179T, pH 7.0
245
ferrocytochrome b5
-
mutant G179A, pH 7.0
400
ferrocytochrome b5
-
wild-type, pH 7.0
600
ferrocytochrome b5
-
pH 7.0, 25C
0.733
NADH
P00387
wild-type, cosubstrate ferricyanide, 25C, pH 7.0
0.8
NADH
P00387
mutant P275L, cosubstrate ferricyanide, 25C, pH 7.0
21.7
NADH
-
mutant enzyme P247L, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P247L, ferricyanide as electron acceptor
53
NADH
-
G273 mutant enzyme
77
NADH
-
H49E mutant enzyme
100
NADH
-
pH 7.0, 25C,T66V mutant enzyme
180
NADH
-
Y65A mutant enzyme
250
NADH
-
D239S/F251R mutant enzyme, pH 7.0, 25C
310
NADH
-
DELTAF272 mutant enzyme
332
NADH
-
-
333
NADH
-
D239T mutant enzyme, pH 7.0, 25C
354
NADH
-
mutant enzyme P247A, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P247A, ferricyanide as electron acceptor
367
NADH
-
F251Y mutant enzyme, pH 7.0, 25C
375
NADH
-
S99V mutant enzyme
390
NADH
-
native enzyme
403
NADH
-
R63A mutant enzyme
412
NADH
-
R63Q mutant enzyme
433
NADH
-
D239S mutant enzyme, pH 7.0, 25C
435
NADH
-
S99A mutant enzyme
440
NADH
-
H49A mutant enzyme
467
NADH
-
D239S/F251Y mutant enzyme, pH 7.0, 25C
500
NADH
-
-
500
NADH
-
F251R mutant enzyme, pH 7.0, 25C
501
NADH
-
Y65F mutant enzyme
515
NADH
-
R63K mutant enzyme
517
NADH
-
D239E mutant enzyme, pH 7.0, 25C
540
NADH
-
mutant enzyme P248L, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P248L, ferricyanide as electron acceptor
559
NADH
-
mutant enzyme P248A, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P248A, ferricyanide as electron acceptor
570
NADH
-
recombinant wild-type enzyme
681
NADH
-
mutant enzyme P249A, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P249A, ferricyanide as electron acceptor
710
NADH
-
H49K mutant enzyme
717
NADH
-
D239T/F251R mutant enzyme, pH 7.0, 25C
742
NADH
-
ferricyanide as electron acceptor; wild type enzyme, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
750
NADH
-
H49Y mutant enzyme
754
NADH
-
mutant D239G, pH 7.0; mutant E255-, pH 7.0; mutant G291D, pH 7.0; wild-type, pH 7.0
800
NADH
-
wild type enzyme, pH 7.0, 25C
851
NADH
-
S99T mutant enzyme
909
NADH
-
K97R mutant enzyme
984
NADH
-
pH 7.0, 25C,T66A mutant enzyme
1059
NADH
-
mutant enzyme P249L, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C; mutant P249L, ferricyanide as electron acceptor
1060
NADH
-
K97A mutant enzyme
1100
NADH
-
recombinant wild-type enzyme
1100
NADH
-
pH 7.0, 25C, wild type enzyme
1150
NADH
-
pH 7.0, 25C,T66S mutant enzyme
3
NADPH
-
mutant E255-, pH 7.0
5.2
NADPH
-
D239E mutant enzyme, pH 7.0, 25C
8
NADPH
-
mutant G179V, pH 7.0
12
NADPH
-
mutant G179T, pH 7.0
17
NADPH
-
mutant G179P, pH 7.0
19
NADPH
-
mutant G291D, pH 7.0
33
NADPH
-
wild type enzyme, pH 7.0, 25C
33
NADPH
-
wild-type, pH 7.0
33
NADPH
-
wild-type, pH 7.0
48
NADPH
-
mutant G179A, pH 7.0
50
NADPH
-
F251R mutant enzyme, pH 7.0, 25C; F251Y mutant enzyme, pH 7.0, 25C
190
NADPH
-
mutant D239G, pH 7.0
200
NADPH
-
D239S/F251R mutant enzyme, pH 7.0, 25C
217
NADPH
-
D239S mutant enzyme, pH 7.0, 25C
267
NADPH
-
D239T mutant enzyme, pH 7.0, 25C
297
NADPH
-
-
417
NADPH
-
D239S/F251Y mutant enzyme, pH 7.0, 25C
550
NADPH
-
D239T/F251R mutant enzyme, pH 7.0, 25C
kcat/KM VALUE [1/mMs-1]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
25530
ferricyanide
-
mutant enzyme P248A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
132
29620
ferricyanide
-
mutant enzyme P247L, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
132
31670
ferricyanide
-
mutant enzyme P249A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
132
32140
ferricyanide
-
mutant enzyme P248L, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
132
32570
ferricyanide
-
mutant enzyme P247A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
132
37500
ferricyanide
-
mutant enzyme P249L, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
132
46610
ferricyanide
-
wild type enzyme, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
132
80700
ferricytochrome b5
-
mutant enzyme P247A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
1034
87700
ferricytochrome b5
-
mutant enzyme P248A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
1034
108600
ferricytochrome b5
-
wild type enzyme, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
1034
120500
ferricytochrome b5
-
mutant enzyme P249A, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
1034
880
NADH
-
mutant enzyme P247L, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
8
20670
NADH
-
mutant enzyme P247A, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
8
23220
NADH
-
mutant enzyme P248A, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
8
23260
NADH
-
mutant enzyme P249A, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
8
40000
NADH
-
mutant enzyme P248L, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
8
67640
NADH
-
wild type enzyme, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
8
68320
NADH
-
mutant enzyme P249L, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25C
8
Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.00021
myricetin
-
versus NADH, pH 7.5, 24-25C
0.08
ADP
-
-
additional information
additional information
-
inhibition kinetics
-
IC50 VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.0045
(+)-catechin
-
pH 7.5, 22C
0.0098
(+)-taxifolin
-
pH 7.5, 24-25C
0.0032
(-)-epicatechin
-
pH 7.5, 22C
0.036
apigenin
-
pH 7.5, 22C
0.00011
luteolin
-
pH 7.5, 22C
0.0024
luteolin-7-O-glucoside
-
pH 7.5, 22C
0.00081
morin
-
pH 7.5, 22C
0.00037
myricetin
-
pH 7.5, 24-25C
0.0015
myricetin
-
pH 7.5, 22C
0.0011
quercetin
-
pH 7.5, 22C
0.0012
quercitrin
-
pH 7.5, 22C
0.057
rutin
-
pH 7.5, 22C
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
0.00072
-
liver microsomes, reduction of 1,2-dihydro-8-(4-methylpiperazin-1-yl)-4-phenylimidazol[3,2-e]pyrazine 5-oxide
0.0039
-
activity in liver microsomes
0.036 - 0.109
-
activity in lysates of different cancer cell lines
0.0648
-
activity in liver microsomes in the presence of 2 mM MgCl2
0.0888
-
activity in liver microsomes in the presence of 2 mM CaCl2
0.109
-
reduction of aquacobalamin
0.372
-
in the presence of 0.1% Triton X-100
1.69
-
methemoglobin-ferrocyanide reductases assay
2.042
-
reduction of cytochrome b5
3.5
-
low MW aggregate, nitro blue tetrazolium as electron acceptor
10.6
-
low MW aggregate, cytochrome b as electron acceptor
14.9
-
pH 7.0, 25C, substrate ferricyanide
96.3
-
recombinant enzyme
137
-
-
138
-
low MW aggregate, dichlorophenolindophenol as electron acceptor
230.5
-
high MW aggregate
300
A8WEG5
-
611.1
-
low MW aggregate, ferricyanide as electron acceptor
628
-
purified on Mono Q, ferricyanide reduction
670
-
-
1007
-
reduction of ferricyanide
1200 - 1300
-
ferricyanide reduction
1400
-
recombinant enzyme
1470
-
enzyme from liver plasma membrane
1510
-
liver microsomal enzyme, ferricyanide as electron acceptor
2480
-
reduction of ferricyanide
additional information
-
0.00017 mmol ferricyanide reduced/min/10000000 cells, activity in neutrophils
additional information
-
102.0 units/mg, 1 unit is defined as the change of 1 absorbance unit at 600 nm/min
additional information
-
28.6 units, 1 unit is defined as the amount of enzyme changing 0.001 of DELTAAbsorbance/min
additional information
-
41.25 units, 1 unit is defined as the amount of enzyme changing 0.001 of DELTAAbsorbance/min
additional information
-
enzyme activity in erythrocytes of mammalian enzymes and rainbow trout, overview
additional information
-
enzyme activity in erythrocytes of rainbow trout compared to mammalian enzymes, overview
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
5 - 5.7
-
-
5.2
-
NADH-methemoglobin-ferrocyanide
5.5
-
acceptor ferricyanide
5.6
-
steady decrease above
5.7 - 8
-
rapid decrease above
6 - 8
-
acceptor Phascolopsis gouldii cytochrome b5
6
Q1HA49
around, recombinant enzyme
6.4
-
citrate-phosphate buffer
6.5 - 8.5
-
NADH-ferricyanide
6.5
-
Tris-phosphate buffer
6.6 - 7.5
-
assay at
6.6
-
Tris-maleate buffer
6.8 - 7.5
-
-
6.8
-
reduction of cytochrome c
7 - 7.5
-
-
7
-
triethanolamine buffer
7.2 - 8.4
-
assay at, dependent on assay method
7.5
A8WEG5
no significant difference in the pH range of 6-8
7.5
-
assay at
8
-
acceptor dichlorphenolindophenol
additional information
-
no distinct optimum with phosphate or Tris-HCl buffer
pH RANGE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
5 - 8
-
depending on acceptor
6.6 - 7.5
-
enzyme activity is higher at pH 7.5 compared to pH 6.6
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
22
-
assay at room temperature
24 - 25
-
assay at
25
-
assay at
40
A8WEG5
-
pI VALUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
8.9
Q1HA49
calculated from sequence
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SOURCE
-
transcripts of L, X and Y mRNAs are detected
Manually annotated by BRENDA team
-
transcript of R mRNA is detected
Manually annotated by BRENDA team
P00387
Cytb5r enzyme activity is drastically reduced in all patients with recessive hereditary methemoglobinemia. Eight different mutations are detected among the twelve mutated alleles identified
Manually annotated by BRENDA team
-
contains the soluble isozyme but no microsomal isozyme
Manually annotated by BRENDA team
-
highest activity in confluently grown cells
Manually annotated by BRENDA team
-
transcripts of L, X and Y mRNAs are detected
Manually annotated by BRENDA team
-
NaCl application results in a significant increase in the activity
Manually annotated by BRENDA team
-
transcripts of L, X and Y mRNAs are detected
Manually annotated by BRENDA team
-
transcripts of L, X, R and Y mRNAs are detected
Manually annotated by BRENDA team
-
developing seed
Manually annotated by BRENDA team
-
transcripts of L, X and Y mRNAs are detected
Manually annotated by BRENDA team
additional information
Q3TDX8
exon 12 deletion variant is not found in kidney, lung, liver, and heart
Manually annotated by BRENDA team
additional information
Q68EJ0
exon 12 deletion variant is not found in kidney, lung, liver, and heart
Manually annotated by BRENDA team
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
-
soluble isozyme
Manually annotated by BRENDA team
-
may be a proteolytic product of the membrane enzyme
Manually annotated by BRENDA team
-
2 forms in erythrocytes: a soluble and a membrane-bound enzyme which represents the majority
Manually annotated by BRENDA team
-
protein lacking N-myristoylation
Manually annotated by BRENDA team
-
enzyme binds in vitro to a variety of membrane preparations, protease treatment removes a hydrophobic segment that is responsible for membrane binding
Manually annotated by BRENDA team
-
subcellular distribution, high concentration in outer mitochondrial membrane
Manually annotated by BRENDA team
-
membrane-binding domain resides in the NH2-terminal region
Manually annotated by BRENDA team
-
cytoplasmic side of erythrocyte membrane
Manually annotated by BRENDA team
-
microsomal enzyme, COOH-terminal domain constitutes the hydrophobic moiety which is responsible for membrane-binding
Manually annotated by BRENDA team
-
membrane of endoplasmic reticulum, outer mitochondrial membrane, tightly bound to cytoplasmic face of membrane
Manually annotated by BRENDA team
-
full length form contains a 3 kDa membrane anchoring domain
Manually annotated by BRENDA team
Q7L1T6
Cyb5R3
-
Manually annotated by BRENDA team
-
the microsomal isozyme consists of one hydrophobic membrane-anchoring domain and a larger hydrophilic flavin catalytic domain
-
Manually annotated by BRENDA team
-
outer membrane enzyme complex
Manually annotated by BRENDA team
-
formed by alternative splicing
-
Manually annotated by BRENDA team
-
truncated form lacking the membrane anchoring domain
-
Manually annotated by BRENDA team
-
truncated form lacking the membrane anchoring domain, present in erythrocytes
-
Manually annotated by BRENDA team
-
N-myristoylation is required for correct targeting
Manually annotated by BRENDA team
additional information
-
possible conformation of membrane binding domain
-
Manually annotated by BRENDA team
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
25000
-
liver, cytosol, gel filtration, sucrose density gradient centrifugation
394227
27000
-
gel filtration
394228
27000
-
sedimentation equilibrium
394230
28000
-
gel filtration
394230
30000
-
erythrocytes, cytosol, gel filtration
394217
30000
-
enzyme from liver cytosol, gel filtration
394227
30000
-
SDS-PAGE
657675
30810
-
calculated from amino acid sequence
699061
31000
-
SDS-PAGE
699061
32000
Q6BCY4
SDS-PAGE
658252
33000
-
recombinant enzyme, gel filtration
394199
33000
-
gel filtration
394218
34700
-
erythrocytes, cytosol, gel filtration, calculation from FAD content
394218
36000
-
SDS-PAGE, 32000 Da protein + 4000 Da His-tag
659784
44000
-
gel filtration
394206
135000
-
gel filtration
394205
200000
-
oligomeric aggregate of detergent-solubilized enzyme in aqueous media, gel filtration
394194
365000
-
-
394223
365000
-
oligomeric aggregates of detergent solubilized enzyme, sedimentation equilibrium
394229
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
?
-
x * 35000, SDS-PAGE
?
-
x * 31000, SDS-PAGE
?
A8WEG5
x * 30000, SDS-PAGE
?
-
x * 34000, SDS-PAGE
?
-
x * 34000, SDS-PAGE
?
-
x * 22000, SDS-PAGE
?
Q1HA49
x * 29000, SDS-PAGE
?
-
x * 33000, SDS-PAGE
?
-
x * 33000, SDS-PAGE, gel filtration in the presence of 6 M guanidine hydrochloride, gel filtration in the presence of 0.5% sodium deoxycholate
?
-
x * 38400, liver microsomes, sedimentation equilibrium
?
-
x * 31000, may occur from protease cleavage of the 33000 Da protein during purification
?
Q9ZPN0
x * 31170, deduced from nucleotide sequence
?
-
x * 32000, enzyme from erythrocyte cytosol and liver microsomal enzyme solubilized with cathepsin D, SDS-PAGE, x * 36000, enzyme from erythrocyte membrane, SDS-PAGE
?
-
x * 30000, lysosome-solubilized enzyme, SDS-PAGE, x * 35000, detergent-solubilized enzyme, SDS-PAGE
?
-
x * 32000, enzyme from liver microsomes solubilized with Triton X-100, SDS-PAGE
?
-
x * 31365, mass spectrometry of histidine-tagged variant of the soluble, catalytic diaphorase domain, comprising residues I33 to F300
?
-
x * 33000 (soluble domain), SDS-PAGE
?
-
x * 34000, Western blot analysis
?
-
x * 42800, chimeric protein NADH-cytochrome b5 reductase-cytochrome b5, confirmed by SDS-PAGE
?
Mucor racemosus PTCC 5305
-
x * 30000, SDS-PAGE
-
monomer
-
1 * 28000, SDS-PAGE
monomer
-
1 * 32000, SDS-PAGE
monomer
-
1 * 33000, soluble enzyme from erythrocyte, SDS-PAGE
monomer
-
1 * 33100, SDS-PAGE
tetramer
-
4 * 34500, SDS-PAGE
monomer
-
1 * 30000, recombinant enzyme, SDS-PAGE, 1 * 30588, recombinant enzyme, MALDI-TOF mass spectrometry
additional information
-
liver: membrane binding domain located at NH2-terminal site of protein, 6400-6500 Da
additional information
-
liver: hydrophobic domain of approx. 30 amino acids located at COOH-terminal site of protein
POSTTRANSLATIONAL MODIFICATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
lipoprotein
-
amphipathic membrane protein containing a hydrophilic, catalytic domain and a smaller hydrohobic membrane-binding domain
lipoprotein
-
myristic acid at NH2-terminus, amide bond, no ester bond
lipoprotein
-
-
lipoprotein
-
N-myristoylation is required for correct targeting to mitochondria. Part of the protein is targeted to the endoplasmic reticulum without myristoylation, which interferes with interaction of the nascent chain with signal recognition particle, while a portion is myristoylated and targeted to mitochondria
Crystallization/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
sitting drop vapor diffusion method, using 2 M (NH4)2SO4, 100 mM sodium/potassium phosphate, pH 6.2, 200 mM Li2SO4, at 4C
Q7L1T6
sitting-drop vapor diffusion method
-
vapor equilibrium method, 3.6% protein solution, 30% polyethyleneglycol 4000, preliminary X-ray data
-
hanging-drop vapour-diffusion method
-
sitting drop method
-
sitting drop method, complete data set collected for the D239T mutant enzyme
-
sitting drop method, reservoir: 8% poly ethylene glycol 6000, 5% 2-methyl-2,4-pentanediol in 100 mM 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid, pH 7.5, X-ray structure, resolution: enzyme 2.0 A, enzyme-NAD+ complex, 2.3 A
-
fully reduced form and the oxidized form of the purified liver enzyme, X-ray diffraction structure determination and analysis at 1.68 A resolution
-
vapor diffusion method, 5 mg/ml protein, 12.5% polyethylenglycol 4000, 50 mM potassium phosphate pH 6.0-8.0, 0.1 mM EDTA, preliminary X-ray data
-
X-ray structure, 2.4 A resolution
-
pH STABILITY
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
7 - 9
-
-
394231
7.5 - 8.1
-
-
394225
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
-12
-
stable
394231
0 - 5
-
several days
394231
21
-
several h
394231
40
Q1HA49
30 min, less than 10% loss of activity
685672
50
Q1HA49
30 min, 30 min, about 80% loss of activity
685672
51
-
denaturation temperature. The difference in the hydrophobic interactions in the Physarum polycephalum and human cyt b5R proteins is the primary factor underlying the lower denaturation temperature of Physarum polycephalum cyt b5R
684209
55
Q1HA49
10 min, complete loss of activity
685672
GENERAL STABILITY
ORGANISM
UNIPROT
LITERATURE
inactivation during dialysis is prevented by NADH
-
enzyme from erythrocyte loses its activity in the absence of EDTA after 5 d at 4C
-
0.2% phosphatidycholine liposomes or Triton X-100 stabilize
-
freezing/thawing: 50% inactivation
-
hydrophilic domain is unfolded at approx. 1 M guanidinium hydrochloride whereas much higher concentrations are required for denaturation of the hydrophobic domain
-
Triton X-100 stabilizes
-
dithiothreitol is essential for stability
-
EDTA is essential for stability
-
inactivation caused by solubilization with detergents, activity restored by phosphatidylcholine
-
phosphate stabilizes
-
unstable, 40% loss of activity at 0C overnight, 1 mg/ml gelatin stabilizes, FAD protects against inactivation
-
application of HPLC during purification causes inactivation
-
OXIDATION STABILITY
ORGANISM
UNIPROT
LITERATURE
O2, solubilized enzyme very sensitive to atmospheric oxygen
-
394194
STORAGE STABILITY
ORGANISM
UNIPROT
LITERATURE
0C, at least 1 month
-
0C, at least 1 week
-
-20C, pH 7.5-8.1, 0.5 mM EDTA, protein concentration above 0.02 mg/ml
-
4C, phosphate buffered saline, pH 7.4, protein concentration 2-3 mg/ml, stable for 3 weeks
-
-20C, 25 mM phosphate buffer, pH 7.6, 1 mM EDTA, 0.1 mM dithiothreitol, at least a few months
-
-20C, several months, no loss of activity
-
-70C, concentrated solution, several months, no loss of activity
-
-70C, several months, no loss of activity
-
4C, anaerobic conditions, EDTA, dithiothreitol, several months
-
frozen, 50 mM potassium phosphate buffer, pH 7.5, 1 mM EDTA, several weeks
-
-90C, oxidized state, 1 month
-
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
affinity chromatography on ADP-agarose
-
lysosome-solubilization
-
native enzyme from liver
-
native enzyme from liver by anion-exchange chromatography of the detergent solubilized microsomes on two successive DEAE-cellulose columns and an affinity chromatography on adenosine 5'-diphosphate-agarose, to homogeneity
-
native enzyme from liver microsomes by anion exchange chromatography and affinity chromatography
-
separation of membrane binding and catalytic domain
-
DEAE-cellulose, DEAE-Sephadex, hydroxyapatite
-
native membrane-bound isozyme by solubiization from membranes, anion exchange chromatography, and affinity chromatography
-
Ni2+-NTA bead chromatography, HiTrap Q column chromatography, HiTrap phenyl column chromatography, and Superdex 200 gel filtration
Q7L1T6
recombinant enzyme
-
recombinant protein
-
recombinant wild-type, K110A, K110M and K110R mutant enzyme
-
recombinant wild-type, K41A, K125A and K163A mutant enzyme
-
Triton X-100, DEAE-cellulose, CM-cellulose, 5'-ADP-agarose
-
polyethylene glycol precipitation, ADP-agarose
-
DEAE-cellulose, 5'-ADP-agarose affinity chromatography
-
recombinant enzyme
Q1HA49
chimeric protein NADH-cytochrome b5 reductase-cytochrome b5
-
lysosome-solubilization
-
polyethylene glycol precipitation, DEAE-cellulose, hydroxylapatite, ADP-agarose
-
recombinant enzyme
-
recombinant enzyme, affinity chromatography on 5'-ADP-agarose
-
recombinant enzymes
-
recombinant enzymes purified from Escherichia coli
-
Triton X-100, anion exchange chromatography, gel filtration
-
wild-type, K110R, K110H, K110A, K110E and K110Q mutant enzymes
-
recombinant enzyme
-
DEAE-trisacryl, Blue ultrogel, Mono Q
-
ammonium sulfate precipitation, DEAE-Sepharose CL-6B column chromatography, 5'-ADP-agarose (or 5'-AMP-agarose) gel column chromatography, and Ni-NTA-agarose column chromatography; soluble domain
-
lysosome- and detergent-solubilization
-
recombinant enzymes from Escherichia coli
-
recombinant wild-type, H49A, H49E, H49K, H49Y, and DELTAF272 mutant enzyme
-
recombinant wild-type, K97A, K97R, S99A, S99T, S99V, R63A, R63Q, R63K, Y65A and Y65F mutant enzymes
-
DEAE-trisacryl, Blue ultrogel, Mono Q
-
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
cloning of cDNA
-
enzyme coexpressed together with cytochrome b5 and CYP2E1or with CYP2E1 but without cytochrome b5 in Salmonella typhimurium strain 7108
-
expressed in COS-7 cells
Q6BCY4
expressed in Escherichia coli as alpha-thrombin-cleavable fusion protein
-
expressed in Escherichia coli as His-tag fusion protein
-
expressed in Escherichia coli BL21(DE3) cells
Q7L1T6
expression in Escherichia coli
-
expression of wild-type, K110A, K110M and K110R mutant enzymes in Escherichia coli
-
expression of wild-type, K41A and K125A mutant enzyme in Escherichia coli
-
heterologous expression in Escherichia coli or in yeast cells via different expression vectors, in Aspergillus oryzae using pNGA142, Salmonella typhimurium using pIN, in Spodoptera frugiperda Sf9 insect cells using pFASTBAC baculovirus vectors, in cell-free systems, in plant cells using pRT, in lymphoid cells using Epstein-Barr virus, and in CHO cells using SV40 transfection method
-
expressed in Pichia pastoris
-
His-tag
A8WEG5
expressed in Escherichia coli BL21(DE3)-RIL
-
expression in Escherichia coli
-
expression of a soluble fusion protein comprising a b-type cytochrome containing domain and a FAD-containing domain
-
expression of wild-type, K110R, K110H, K110A, K110E and K110Q mutant enzymes in Escherichia coli
-
mutant enzymes expressed in Escherichia coli BL21(DE3)-RIL as His-tag fusion proteins
-
wild type and mutant enzyme expressed in Escherichia coli BL21-CodonPlus (DE3)-RIL
-
heterologous expression in Saccharomyces cerevisiae
-
all mutants expressed in soluble form in Escherichia coli BL21
-
expressed in Escherichia coli BL21(DE3) cells; soluble domain, His-tag
-
expression of wild-type, H49A, H49E, H49K, H49Y, and DELTAF272 mutant enzymes in Escherichia coli
-
expression of wild-type, K97A, K97R, S99A, S99T, S99V, R63A, R63Q, R63K, Y65A and Y65F mutant enzymes in Escherichia coli
-
cloning of cDNA, expression in Saccharomyces cerevisiae
Q9ZPN0
expression in Saccharomaces cerevisiae
Q8W2K4
EXPRESSION
ORGANISM
UNIPROT
LITERATURE
a significant increase in the activity of cytochrome b5 reductase is observed after trichloroaceticacid treatment at 0.2% (w/v) (about 12 mM) concentration in drinking water ad libitum for 60 days as compared to control groups
-
ENGINEERING
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
A178T
-
natural mutation found in patient with type I recessive congenital methaemoglobinaemia, 16.6% of wild-type enzyme activity
A179T
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
A179V
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
C204R
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
C204Y
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
D239G
-
natural mutation found in patient with type I recessive congenital methaemoglobinaemia, mutation of NADH-binding lobe. Mutant shows decreased specificity for NADH and increased specificity for NADPH, 28.5% of wild-type enzyme activity
D239T
-
the mutation changes the enzme preference for NADH to one for NADPH. Diseases related to CyB5R dysfunctions due to mutations in the gene encoding the enzyme, detailed overview
D240G
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
E213K
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
E255-
-
natural mutation found in patient with type I recessive congenital methaemoglobinaemia, mutation of NADH-binding lobe. Mutant retains stoichiometric levels FAD comparable to wild-type
F157C
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
G143D
-
mutation in the NADH-cytochrome b5 reductase gene in an Indian patient with type I recessive hereditary methemoglobinemia
G144D
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
G291D
-
natural mutation found in patient with type I recessive congenital methaemoglobinaemia, mutation of NADH-binding lobe. Mutant retains stoichiometric levels FAD comparable to wild-type and 35.2% of wild-type enzyme activity
G292D
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
G72A
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
G75S
-
natural mutation isolated in patient with recessive congenital methemoglobinaemia. Mutant retains stoichiometric levels of FAD, but shows decreased catalytic efficiency and reduced protein stability
G75S/V252M
-
natural mutation isolated in patient with recessive congenital methemoglobinaemia. Mutant retains stoichiometric levels of FAD, but shows decreased catalytic efficiency and reduced protein stability
G76S
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
I216T
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
I85S
-
mutation in patients with recessive congenital methaemoglobinaemia
I85S
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
K110A
-
200fold elevated Km value for NADH, 85% of kcat
K110M
-
1120fold elevated Km value for NADH
K110R
-
similar kinetic properties as wild-type
K125A
-
5.3fold elevated Km value for cytochrome b5
K163A
-
5.7fold elevated Km value for cytochrome b5
K41A
-
6.3fold elevated Km value for cytochrome b5
L149P
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
L217P
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
L218P
-
the mutation is associated with type I recessive congenital methemoglobinemia
L239R
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
L73P
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
P145L
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
P145S
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
P275L
P00387
natural mutant from a patient with recessive congenital methemoglobinemia. Significant decrease in the affinity toward the physiological reducing substrate, NADH, without affecting the activity
P276L
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
P65L
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
P96H
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
R159-/D239G
-
natural mutation found in patient with type I recessive congenital methaemoglobinaemia, 40.8% of wild-type enzyme activity
R241G
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
R259W
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
R46W
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
R50Q
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
R58Q
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
S128P
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
S54R
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
V106M
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
V252M
-
natural mutation isolated in patient with recessive congenital methemoglobinaemia. Mutant retains stoichiometric levels of FAD, but shows decreased catalytic efficiency and reduced protein stability
V253M
-
mutation in patients with recessive congenital methaemoglobinaemia
V253M
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
D239E
-
decreased activity with NADH and NADPH
D239S
-
significantly increased activity with NADPH
D239S/F251R
-
specific for NADPH
D239S/F251Y
-
bispecific for NADH and NADPH
D239T
-
specific for NADPH, 11fold preference for NADPH over NADH
D239T/F251R
-
specific for NADPH
F251R
-
minor effects on activity
F251Y
-
minor effects on activity
G179A
-
mutant preceeding the 180GxGxxP185 motif bindin the adenosine moiety of NAD(P)H. Incorporation of FAD and adsortion and CD spectra similar to wild-type. Decrease in NADH:ferricyanide activity and affinity for NADH
G179P
-
mutant preceeding the 180GxGxxP185 motif bindin the adenosine moiety of NAD(P)H. Incorporation of FAD and adsortion and CD spectra similar to wild-type. Decrease in NADH:ferricyanide activity and affinity for NADH
G179T
-
mutant preceeding the 180GxGxxP185 motif bindin the adenosine moiety of NAD(P)H. Incorporation of FAD and adsortion and CD spectra similar to wild-type. Decrease in NADH:ferricyanide activity and affinity for NADH
G179V
-
mutant preceeding the 180GxGxxP185 motif bindin the adenosine moiety of NAD(P)H. Incorporation of FAD and adsortion and CD spectra similar to wild-type. Decrease in NADH:ferricyanide activity and affinity for NADH
K110A
-
strongly reduced kcat for ferricyanide and cytochrome b5
K110E
-
strongly reduced kcat for ferricyanide and cytochrome b5
K110H
-
strongly reduced kcat for ferricyanide and cytochrome b5
K110Q
-
very low kcat for ferricyanide and cytochrome b5
K110R
-
reduced kcat for ferricyanid and cytochrome b5
P144L
-
28% of wild type activity, reduced temperature stability and resistance against limited proteolysis with trypsin, increased affinity for NAD+
P144L/L148P
-
8% of wild type activity, reduced temperature stability and resistance against limited proteolysis with trypsin, increased affinity for NAD+
P92A
-
mutation preceeding the conserved motif RxYTSxxSN, FAD is bound in 1:1 cofactor:protein stoichiometry
P92G
-
mutation preceeding the conserved motif RxYTSxxSN, FAD is bound in 1:1 cofactor:protein stoichiometry
P92S
-
mutation preceeding the conserved motif RxYTSxxSN, FAD is bound in 1:1 cofactor:protein stoichiometry
R159
-
deletion mutant, could not be successfully expressed
S127P
-
caused methemoglobinemia type II, FAD is displaced from its binding site by NADH, Km for NADH is strongly increased
Y93A
-
mutation preceeding the conserved motif RxYTSxxSN, FAD is bound in 1:1 cofactor:protein stoichiometry
Y93D
-
mutation preceeding the conserved motif RxYTSxxSN, FAD is bound in 1:1 cofactor:protein stoichiometry
Y93F
-
mutation preceeding the conserved motif RxYTSxxSN, FAD is bound in 1:1 cofactor:protein stoichiometry
Y93H
-
mutation preceeding the conserved motif RxYTSxxSN, FAD is bound in 1:1 cofactor:protein stoichiometry
Y93S
-
mutation preceeding the conserved motif RxYTSxxSN, FAD is bound in 1:1 cofactor:protein stoichiometry
Y93W
-
mutation preceeding the conserved motif RxYTSxxSN, FAD is bound in 1:1 cofactor:protein stoichiometry
H49A
-
reduced kcat
H49E
-
elevated Km value for cytochrome b5, strongly reduced kcat
H49K
-
reduced Km value for cytochrome b5
H49Y
-
similar to wild-type
K97A
-
mutation in flavin-binding motif
K97R
-
mutation in flavin-binding motif
P247A
-
proposed NADH-binding site, soluble domain is analyzed, the mutant shows increased Km and decreased kcat values for NADH and cytochrome b5, as well as increased Km and kcat values for ferricyanide compared to the wild type enzyme
P247L
-
proposed NADH-binding site, soluble domain is analyzed, the mutation significantly decreases kcat with slight increase (about 2fold) in Km for the physiological electron donor NADH. However, Km and kcat values for the electron acceptors (both cytochrome b5 and ferricyanide) are decreased significantly
P248A
-
proposed NADH-binding site, soluble domain is analyzed, the mutant shows increased Km and decreased kcat values for NADH and cytochrome b5, as well as increased Km and kcat values for ferricyanide compared to the wild type enzyme
P248L
-
proposed NADH-binding site, soluble domain is analyzed, the mutant shows increased Km and decreased kcat values for NADH and ferricyanide compared to the wild type enzyme
P249A
-
proposed NADH-binding site, soluble domain is analyzed, the mutation affects the Km (NADH) values to increase slightly by a factor of 3 compared to the wild type enzyme
P249L
-
proposed NADH-binding site, soluble domain is analyzed, the mutant shows increased Km and kcat values for NADH, ferricyanide and cytochrome b5 compared to the wild type enzyme
R63A
-
mutation in flavin-binding motif
R63K
-
mutation in flavin-binding motif
R63Q
-
mutation in flavin-binding motif
S99A
-
mutation in flavin-binding motif
S99T
-
mutation in flavin-binding motif
S99V
-
mutation in flavin-binding motif
T66A
-
Km for NADH is not affected, Km for cytochrome b5 is significantly enhanced
T66S
-
Km for NADH is not affected
T66V
-
turnover is reduced to 10% of the native enzyme, Km for NADH is not affected, Km for cytochrome b5 is significantly enhanced
Y65A
-
mutation in flavin-binding motif
Y65F
-
mutation in flavin-binding motif
additional information
-
three T-DNA insertional knockout mutants of the gene CBR1 encoding cytochrome b5 reductase showing distorted segregation, with greatly reduced penetrance through the male gametophyte. In fertilization experiments, pollen of cbr1-2 plants germinated on wild-type and cbr1-2 stigmas, but the majority of pollen tubes stopped growing prior to reaching the ovules, leading to severely reduced fertilization and seed set
additional information
-
expression of histidine-tagged variant of the soluble, catalytic diaphorase domain, comprising residues I33 to F300. Fragment retains both NADH:ferricyanide reductase and NADH:cytochrome b5 reductase activities
M127V
-
naturally occuring mutation causing the RCM phenotype depending on homozygosity/heterozygosity or other additional mutations
additional information
-
naturally occurring mutations of CYB5R3 detected in patients with recessive congenital methaemoglobinaemia
L148P
-
31% of wild type activity, reduced temperature stability and resistance against limited proteolysis with trypsin, increased affinity for NAD+
additional information
-
a chimeric protein NADH-cytochrome b5 reductase-cytochrome b5 is constructed
Renatured/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
reconstitution
-
APPLICATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
drug development
-
flavonoids, regarding b5 reductase inhibition, indicate a potential for significant flavonoiddrug and/or flavonoidxenobiotic interactions which may have important therapeutic and toxicological outcomes for certain drugs and/or xenobiotics.
analysis
-
potential use of the enzyme as biosensor
diagnostics
-
potential use of the enzyme in diagnostic areas
industry
-
potential use of the enzyme in the food industry
medicine
-
potentially an important enzyme required for the reductive activation of bioreductive drugs that can be used in the treatment of solid tumours
medicine
-
enzyme and cytochrome b5 play a direct role in metabolic activation of antimicrobial prodrug DB289 to furamidine
medicine
-
isolation of mutations leading to type I recessive congenital methaemoglobinaemia
medicine
P00387
natural mutant P275L from a patient with recessive congenital methemoglobinemia shows significant decrease in the affinity toward the physiological reducing substrate, NADH, without affecting the activity
medicine
-
reduction of arylhydroxylamine carcinogens by enzyme and ferricytochrome b5 as a source of individual variability with respect to cancer susceptibility following exposure to arylhydroxylamines
medicine
-
to establish a diagnosis of recessive congenital methaemoglobinaemia (RCM), it is important to demonstrate enzyme deficiency of cb5r and this is usually done using a spectrophotometric method,. RCM type I patients manifest a deficiency of cb5r in erythrocytes only whereas type II patients harbour the deficiency in both erythrocytes and leucocytes
medicine
-
-
analysis
-
detailed analysis of biphasic rate of reduction of cytochrome b5 in membranes with evaluation of data in terms of two-dimensional random walk model. The initial rapid phase is completed within 10 msec and over 90% of cytochrome b5 are reduced in 40 msec