BRENDA home
History
Information on EC 1.6.2.2 - cytochrome-b5 reductase
for references in articles please use BRENDA:EC1.6.2.2Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
EC Tree
1.6.2.2 cytochrome-b5 reductaseIUBMB Comments
A flavoprotein (FAD).
Specify your search results
Word Map
- 1.6.2.2
- erythrocyte
- methemoglobinemia
-
nadph-cytochrome
- hereditary
- reductases
-
cyanosis
- fad
- ferricyanide
- flavoproteins
-
desaturation
- dt-diaphorase
- aniline
-
methb
-
bioreductive
- aminopyrine
- n-demethylase
-
hemolysate
-
amidoxime
-
marc
- medicine
-
mixed-function
- methaemoglobin
-
oxyhemoglobin
-
nadh-binding
-
n-hydroxylated
- diagnostics
- analysis
- industry
- drug development
The expected taxonomic range for this enzyme is: Eukaryota, Bacteria, Archaea
Synonyms
b5 plusb5R, b5/b5R, B5R, cb5r, CBR, CBR1, CBR1A, CBR1B, CyB5R, CYB5R2, 
more
topPlease wait a moment until the data is sorted. This message will disappear when the data is sorted.
SYNONYM 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
B5R
cb5r
CBR
CBR1
CyB5R
CYB5R3
cytochrome b5 reductase
cytochrome b5 reductase 3
dihydronicotinamide adenine dinucleotide-cytochrome b5 reductase
-
-
-
-
NADH cytochrome B5 reductase
NADH-cytochrome b5 reductase
NADH-cytochrome-b5 reductase
-
-
-
-
NADH-dependent cytochrome b5 reductase
NADH-ferricyanide reductase
NADH-ferricytochrome b5 oxidoreductase
-
-
-
-
NADH:cytochrome b5 reductase
NADH:ferricytochrome b5 oxidoreductase
P34/P32
-
-
-
-
P35
-
-
-
-
reduced nicotinamide adeninedinucleotide-cytochrome b5 reductase
-
-
-
-
reductase, cytochrome b5
-
-
-
-
B5R
-
-
-
-
cytochrome b5 reductase
-
-
-
-
NADH-cytochrome b5 reductase
-
-
-
-
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
NADH + 2 ferricytochrome b5 = NAD+ + H+ + 2 ferrocytochrome b5
ordered bi bi mechanism
-
NADH + 2 ferricytochrome b5 = NAD+ + H+ + 2 ferrocytochrome b5
hypothetical mechanism
-
NADH + 2 ferricytochrome b5 = NAD+ + H+ + 2 ferrocytochrome b5
hypothetical mechanism
-
NADH + 2 ferricytochrome b5 = NAD+ + H+ + 2 ferrocytochrome b5
hypothetical mechanism
-
NADH + 2 ferricytochrome b5 = NAD+ + H+ + 2 ferrocytochrome b5
hypothetical mechanism
-
NADH + 2 ferricytochrome b5 = NAD+ + H+ + 2 ferrocytochrome b5
electron-transport chain from NADH to a terminal oxidase desaturase, proposed electron transfer mechanism
-
NADH + 2 ferricytochrome b5 = NAD+ + H+ + 2 ferrocytochrome b5
reaction mechanism, overview
-
NADH + 2 ferricytochrome b5 = NAD+ + H+ + 2 ferrocytochrome b5
Y93 forms contact with the FAD, but neither P92 nor Y93 preceeding the conserved motif RxYTSxxSN coordinating flavin binding are critical for flavin incorporation
NADH + 2 ferricytochrome b5 = NAD+ + H+ + 2 ferrocytochrome b5
-
-
-
-
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
oxidation
-
-
-
-
redox reaction
-
-
-
-
reduction
-
-
-
-
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
PATHWAY SOURCE
PATHWAYS
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
SYSTEMATIC NAME
IUBMB Comments
NADH:ferricytochrome-b5 oxidoreductase
A flavoprotein (FAD).
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
CAS REGISTRY NUMBER
COMMENTARY
9032-25-1
-
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
SUBSTRATE
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
1,2-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+
-
potential bioreductive drug, trivial name RB90740
-
?
2 ferricytochrome b5 + NADPH
2 ferrocytochrome b5 + NADP+ + H+
with NADPH the enzyme shows about 20% of the activity with NADH
-
-
?
2-[4-iodophenyl]-3-[4-nitrophenyl]-5-[2,4-disulfophenyl]-2H tetrazolium monosodium salt + NADH
?
-
-
-
?
aquacobalamin + NADH
reduced aquacobalamin + NAD+
-
in the presence of outer membrane cytochrome b, no activity with cyanocobalamin
-
?
Fe3+-ammonium sulfate + NADH
Fe2+-ammonium sulfate + NAD+
-
strongly elevated by the addition of cytochrome b5
-
?
Fe3+-histidine + NADH
Fe2+-histidine + NAD+
-
strongly elevated by the addition of cytochrome b5
-
?
Fe3+-nitrilotriacetate + NADH
Fe2+-nitrilotriacetate + NAD+
-
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 + ?
-
metabolite of DB289, an antimicrobial prodrug of furamidine
-
-
?
ferricytochrome b5 + 4-(5-(4-[amino(hydroxyamino)methyl]phenyl)-2-furyl)-N'-methoxybenzenecarboximidamide
ferrocytochrome b5 + ?
-
metabolite of DB289, an antimicrobial prodrug of furamidine
-
-
?
ferricytochrome b5 + N-hydroxy-2-amino-1-methyl-6-phenylimidazol[4,5-b]pyridine
ferrocytochrome b5 + ?
-
arylhydroxylamine carcinogen found in grilled meat
-
-
?
ferricytochrome b5 + N-hydroxy-4-aminobiphenyl
ferrocytochrome b5 + ?
-
arylhydroxylamine carcinogen found in cigarette smoke
-
-
?
methemoglobin-ferrocyanide complex + NADH
reduced methemoglobin-ferrocyanide complex + NAD+
-
-
-
?
NADH + ferricytochrome b5 + oxidized soluble guanylate cyclase
NAD+ + H+ + ferrocytochrome b5 + reduced soluble guanylate cyclase
-
-
-
-
?
NADH + oxidized 2,6-dichlorophenolindophenol
NAD+ + H+ + reduced 2,6-dichlorophenolindophenol
NADH + oxidized nitroblue tetrazolium
NAD+ + H+ + reduced nitroblue tetrazolium
-
-
-
-
?
sulfamethoxazole hydroxylamine + NADH
?
-
in the presence of cytochrome b5
-
-
?
2 ferricyanide + NADH
2 ferrocyanide + NAD+ + H+
-
-
-
-
?
2 ferricyanide + NADH
2 ferrocyanide + NAD+ + H+
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
no acceptors: ubiquinone-30, menadione, dihydrofolate, lipoamide
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
poor donor: NADPH
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
artificial acceptor: ferricyanide, high reactivity with NADPH as electron donor
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
poor electron acceptors: methylene blue, ferricytochrome c, O2, oxidized glutathione, methemoglobin
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
artificial electron acceptor in the presence of menadione: cytochrome c
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
additional electron donors: deamino-NADH, 3-acetylpyridine-NADH
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
artificial acceptors: p-benzoquinone, 5-hydroxy-1,4-naphthoquinone, nitroblue-tetrazolium
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
additional acceptor: methemoglobin-ferrocyanide complex
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
involved in metabolism of endogenous compounds such as steroids, drugs, carcinogens, environmental pollutants
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
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+
-
soluble form of erythrocytes: reduction of methemoglobin
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
soluble form of erythrocytes: reduction of methemoglobin
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
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+
-
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+
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+
-
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
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
potassium ferricyanide, cytochrome b5, or NADH-2,6-dichlorophenol-indophenol can act as electron acceptors
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
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+
-
uses both NADH and NADPH as electron donors, artificial acceptors: ferricyanide, 2,6-dichlophenolindophenol
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
low activity with trypsin-solubilized cytochrome b5
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
additional acceptor: hemin
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
poor donor: NADPH
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
additional acceptor: methemoglobin-ferrocyanide complex
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
artificial acceptor: ferricyanide
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
additional acceptor: methemerythrin
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
recombinant enzyme, very low activity with NADPH
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
involved in desaturation of fatty acids
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
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+
-
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+
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+
-
specific for NADH as electron donor, artificial acceptors: ferricyanide, 2,6-dichlorphenolindophenol
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
enzyme complex drives the entire sterol 14-demethylation reaction
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
involved in desaturation of fatty acids
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
membrane bound form of somatic cells: essential for lipid metabolism
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
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 c + NADH
2 ferrocytochrome c + NAD+ + H+
-
increases in the presence of cytochrome b5
-
-
?
2 ferricytochrome c + NADH
2 ferrocytochrome c + NAD+ + H+
-
in the presence of outer membrane cytochrome b
-
?
2 ferricytochrome c + NADH
2 ferrocytochrome c + NAD+ + H+
-
cytochrome b5/cytochrome b5 reductase FAD-domain-fusion protein, NADPH is preferred
-
?
2 ferricytochrome c + NADH
2 ferrocytochrome c + NAD+ + H+
reduces also ferricyanide
-
?
2 ferricytochrome c + NADH
2 ferrocytochrome c + NAD+ + H+
isoforms I and II, 16% and 27% of Fe3+-citrate reduction respectively
-
?
2 ferricytochrome c + NADH
2 ferrocytochrome c + NAD+ + H+
isoforms I and II, 16% and 27% of Fe3+-citrate reduction respectively
-
?
Cu2+-citrate + NADH
Cu+-citrate + NAD+
isoforms I and II, 59 and 47% of Fe3+-citrate reduction respectively
-
?
Cu2+-citrate + NADH
Cu+-citrate + NAD+
isoforms I and II, 59 and 47% of Fe3+-citrate reduction respectively
-
?
Fe3+-ATP + NADH
Fe2+-ATP + NAD+
-
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
-
?
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
?
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
-
?
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
-
r
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
?
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
-
?
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
-
r
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
-
?
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
-
?
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
r
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
-
r
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
?
NADH + oxidized 2,6-dichlorophenolindophenol
NAD+ + H+ + reduced 2,6-dichlorophenolindophenol
-
-
-
?
NADH + oxidized 2,6-dichlorophenolindophenol
NAD+ + H+ + reduced 2,6-dichlorophenolindophenol
-
-
-
?
NADH + oxidized 2,6-dichlorophenolindophenol
NAD+ + H+ + reduced 2,6-dichlorophenolindophenol
-
-
-
-
?
NADH + oxidized 2,6-dichlorophenolindophenol
NAD+ + H+ + reduced 2,6-dichlorophenolindophenol
-
-
-
-
r
NADH + oxidized 2,6-dichlorophenolindophenol
NAD+ + H+ + reduced 2,6-dichlorophenolindophenol
-
-
-
-
?
NADPH + ferricytochrome b5
NADP+ + H+ + ferrocytochrome b5
-
low affinity for NADPH
-
-
?
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
-
-
?
additional information
?
-
-
role of enzyme in fatty acid desaturation and conjugation
-
-
?
additional information
?
-
role of enzyme in fatty acid desaturation and conjugation
-
-
?
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
NATURAL SUBSTRATE
NATURAL PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
NADH + ferricytochrome b5 + oxidized soluble guanylate cyclase
NAD+ + H+ + ferrocytochrome b5 + reduced soluble guanylate cyclase
-
-
-
-
?
sulfamethoxazole hydroxylamine + NADH
?
-
in the presence of cytochrome b5
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
involved in metabolism of endogenous compounds such as steroids, drugs, carcinogens, environmental pollutants
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
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+
-
soluble form of erythrocytes: reduction of methemoglobin
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
soluble form of erythrocytes: reduction of methemoglobin
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
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+
-
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+
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+
-
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
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
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+
-
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
involved in desaturation of fatty acids
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
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+
-
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+
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+
-
enzyme complex drives the entire sterol 14-demethylation reaction
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
involved in desaturation of fatty acids
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
involved in the synthesis of fatty acids and cholesterol, and in the oxidation of xenobiotics
-
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
-
membrane bound form of somatic cells: essential for lipid metabolism
-
?
2 ferricytochrome b5 + NADH
2 ferrocytochrome b5 + NAD+ + H+
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
-
?
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
?
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
-
?
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
?
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
-
?
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
-
?
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
-
?
NADH + ferricytochrome b5
NAD+ + H+ + ferrocytochrome b5
-
-
-
?
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
-
-
?
additional information
?
-
-
role of enzyme in fatty acid desaturation and conjugation
-
-
?
additional information
?
-
role of enzyme in fatty acid desaturation and conjugation
-
-
?
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
COFACTOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
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
cytochrome b5 reductase is composed of one FAD and one NADH binding domain linked by a hinge region
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
-
-
392811, 394195, 394196, 394199, 394200, 394203, 394210, 394213, 394216, 394222, 394225, 394234, 394235, 657460, 657648, 659107, 659784, 672826, 713187
NADH
-
-
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
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
Ca2+
additional information
additional information
-
enzyme does not contain appreciable amounts of iron, copper, manganes, silver, mercury, lead, zinc, cobalt or nickel
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
(5Z)-5-[(9H-fluoren-3-yl)methylidene]-1-(4-methylphenyl)-2-sulfanylidenedihydropyrimidine-4,6(1H,5H)-dione
about 80% inhibition at 0.5 mM
(5Z)-5-{[4-bromo-5-(morpholin-4-yl)furan-2-yl]methylidene}-1-(4-methylphenyl)-2-sulfanylidenedihydropyrimidine-4,6(1H,5H)-dione
about 5% inhibition at 0.5 mM
1-(2-fluorophenyl)-5-[(1-methyl-2,3-dihydro-1H-indol-3-yl)methyl]-2-sulfanylidenedihydropyrimidine-4,6(1H,5H)-dione
about 75% inhibition at 0.5 mM
2-methyl-6-[(phenylsulfanyl)methyl]-2,5-dihydropyrimidin-4(3H)-one
about 5% inhibition at 0.5 mM
4-({[(2S)-2,3-dihydro-1,3-benzoxazol-2-yl]sulfanyl}methyl)tetrahydropyrimidine-2,5-dione
about 45% inhibition at 0.5 mM
5-(prop-2-en-1-yl)-6-propyl-2-sulfanylidene-2,3-dihydropyrimidin-4(1H)-one
about 75% inhibition at 0.5 mM
6-(pentyloxy)-2-sulfanylidene-2,3-dihydropyrimidin-4(1H)-one
about 25% inhibition at 0.05 mM
6-([[(2R)-2,3-dihydro-1,3-benzoxazol-2-yl]sulfanyl]methyl)-2-sulfanylidene-2,3-dihydropyrimidin-4(1H)-one
complete inhibition at 0.05 mM
6-benzyl-2-sulfanylidene-2,3-dihydropyrimidin-4(1H)-one
about 3% inhibition at 0.5 mM
6-pentyl-2-sulfanylidene-2,3-dihydropyrimidin-4(1H)-one
about 25% inhibition at 0.5 mM
6-[(phenylsulfanyl)methyl]-2-sulfanylidene-2,3-dihydropyrimidin-4(1H)-one
complete inhibition at 0.05 mM
6-[(phenylsulfanyl)methyl]pyrimidine-2,4(1H,3H)-dione
about 50% inhibition at 0.5 mM
6-{[(2,6-dichlorophenyl)sulfanyl]methyl}-2-sulfanylidene-2,3-dihydropyrimidin-4(1H)-one
complete inhibition at 0.05 mM
6-{[(4-bromophenyl)sulfanyl]methyl}-2-sulfanylidene-2,3-dihydropyrimidin-4(1H)-one
about 10% inhibition at 0.05 mM
6-{[(4-methylphenyl)sulfanyl]methyl}-2-sulfanylidene-2,3-dihydropyrimidin-4(1H)-one
about 85% inhibition at 0.05 mM
6-{[(propan-2-yl)sulfanyl]methyl}-2-sulfanylidene-2,3-dihydropyrimidin-4(1H)-one
about 18% inhibition at 0.05 mM
benzyl alcohol
-
100 mM, 52% inhibition, reversible, may be due to changes in membrane fluidity
K+ high ionic strength
-
reduction of cytochrome b5 or dichlorphenolindophenol
-
myricetin
-
noncompetitive versus NADH, non-linear relationship indicating non-Michaelis-Menten kinetic binding with respect to cytochrome b5
NAD+
competitive, stronger inhibition of mutant enzymes compared to wild type enzyme
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
-
enzyme inhibition by dietary flavonoids: inhibitor structure-activity analysis, overview. No inhibition by morin, apigenin, (+)-catechin, (-)-epicatechin, naringenin and naringin
-
additional information
-
species-specific sensitivity to methemoglobin induction, in vitro induction of methemoglobin by 1 mM NaNO2, overview
-
additional information
-
the enzyme is not inhibited by Mg2+, Mn2+, or EDTA
-
additional information
-
species-specific sensitivity to methemoglobin induction, in vitro induction of methemoglobin by 1 mM NaNO2, overview
-
additional information
-
species-specific sensitivity to methemoglobin induction, in vitro induction of methemoglobin by 1 mM NaNO2, overview
-
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.007
ferricytochrome c
-
cytochrome b5/cytochrome b5 reductase FAD-domain fusion protein
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
-
0.00104
ferricyanide
-
mutant enzyme P247L, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.00723
ferricyanide
-
wild type enzyme, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.008
ferricyanide
-
cytochrome b5/cytochrome b5 reductase FAD-domain fusion protein
0.01096
ferricyanide
-
mutant enzyme P247A, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.01563
ferricyanide
-
mutant enzyme P248A, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.01568
ferricyanide
-
mutant enzyme P248L, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.02646
ferricyanide
-
mutant enzyme P249A, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.03309
ferricyanide
-
mutant enzyme P249L, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.01353
ferricytochrome b5
-
wild type enzyme, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.0207
ferricytochrome b5
-
mutant enzyme P247A, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.03434
ferricytochrome b5
-
mutant enzyme P248A, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.035
ferricytochrome b5
-
enzyme from liver microsome membrane, solubilized with Triton X-100
0.04481
ferricytochrome b5
-
mutant enzyme P249A, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.045
ferricytochrome b5
-
enzyme from liver microsome membrane, cathepsin D solubilized
0.01097
NADH
-
wild type enzyme, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.0135
NADH
-
mutant enzyme P248L, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.0155
NADH
-
mutant enzyme P249L, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.01713
NADH
-
mutant enzyme P247A, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.02407
NADH
-
mutant enzyme P248A, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.02467
NADH
-
mutant enzyme P247L, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.02928
NADH
-
mutant enzyme P249A, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
0.001
NADPH
-
cytochrome b5/cytochrome b5 reductase FAD-domain fusion protein
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
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 25°C
337
ferricyanide
-
wild type enzyme, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
357
ferricyanide
-
mutant enzyme P247A, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
399
ferricyanide
-
mutant enzyme P248A, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
504
ferricyanide
-
mutant enzyme P248L, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
838
ferricyanide
-
mutant enzyme P249A, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
1241
ferricyanide
-
mutant enzyme P249L, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
8.3
ferricytochrome b5
-
cytochrome b5/cytochrome b5 reductase FAD-domain fusion protein
147
ferricytochrome b5
-
wild type enzyme, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
167
ferricytochrome b5
-
mutant enzyme P247A, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
301
ferricytochrome b5
-
mutant enzyme P248A, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
540
ferricytochrome b5
-
mutant enzyme P249A, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
21.7
NADH
-
mutant enzyme P247L, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
354
NADH
-
mutant enzyme P247A, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
540
NADH
-
mutant enzyme P248L, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
559
NADH
-
mutant enzyme P248A, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
681
NADH
-
mutant enzyme P249A, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
742
NADH
-
wild type enzyme, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C
1059
NADH
-
mutant enzyme P249L, using ferricyanide as cosubstrate, in 100 mM potassium phosphate buffer (pH 7.0) at 25°C