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Information on EC 1.1.1.363 - glucose-6-phosphate dehydrogenase [NAD(P)+]
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EC Tree
1.1.1.363 glucose-6-phosphate dehydrogenase [NAD(P)+]IUBMB Comments
The enzyme catalyses a step of the pentose phosphate pathway. The enzyme from the Gram-positive bacterium Leuconostoc mesenteroides prefers NADP+ while the enzyme from the Gram-negative bacterium Gluconacetobacter xylinus prefers NAD+. cf. EC 1.1.1.49, glucose-6-phosphate dehydrogenase (NADP+) and EC 1.1.1.388, glucose-6-phosphate dehydrogenase (NAD+).
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Word Map
- 1.1.1.363
- citrate
- mesenteroides
-
leuconostoc
-
clarias
- batrachus
- 4-hydroxy-2-nonenal
-
freshwater
-
multicatalytic
- catfish
- hne
-
hne-treated
-
lipogenic
-
8-anilino-1-naphthalenesulfonic
- actinomycin
- pentose
-
disease-related
-
teleost
- synthesis
The expected taxonomic range for this enzyme is: Bacteria, Eukaryota
Reaction Schemes
Synonyms
glu-6-pdh, g6-pdh, glc6pd, pputg6pdh-1, 
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SYNONYM 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
G6PD
G6PDH
G6PDH-1
glucose-6-phosphate dehydrogenase
glucose-6-phosphate dehydrogenase Zwf
NADP+- and NAD+-dependent G6PDH
PputG6PDH-1
zwf-1
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REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
D-glucose 6-phosphate + NAD(P)+ = 6-phospho-D-glucono-1,5-lactone + NAD(P)H + H+
-
-
-
-
D-glucose 6-phosphate + NAD(P)+ = 6-phospho-D-glucono-1,5-lactone + NAD(P)H + H+
mechanism in which His240 acts as the general base that abstracts the proton from the C1-hydroxyl group of glucose 6-phosphate, and the carboxylate group of D177 stabilizes the positive charge that forms on H240 in the transition state. The results also confirm the postulated role of His178 in binding the phosphate moiety of glucose 6-phosphate
-
D-glucose 6-phosphate + NAD(P)+ = 6-phospho-D-glucono-1,5-lactone + NAD(P)H + H+
enzyme PputG6PDH-1 from Pseudomonas putida KT2440 catalyzes the oxidation of D-glucose 6-phosphate using a rapidequilibrium random mechanism
D-glucose 6-phosphate + NAD(P)+ = 6-phospho-D-glucono-1,5-lactone + NAD(P)H + H+
enzyme PputG6PDH-1 from Pseudomonas putida KT2440 catalyzes the oxidation of D-glucose 6-phosphate using a rapidequilibrium random mechanism
-
-
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PATHWAY SOURCE
PATHWAYS
BRENDA
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SYSTEMATIC NAME
IUBMB Comments
D-glucose-6-phosphate:NAD(P)+ 1-oxidoreductase
The enzyme catalyses a step of the pentose phosphate pathway. The enzyme from the Gram-positive bacterium Leuconostoc mesenteroides prefers NADP+ while the enzyme from the Gram-negative bacterium Gluconacetobacter xylinus prefers NAD+. cf. EC 1.1.1.49, glucose-6-phosphate dehydrogenase (NADP+) and EC 1.1.1.388, glucose-6-phosphate dehydrogenase (NAD+).
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SUBSTRATE
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
6-phospho-D-glucono-1,5-lactone + NADPH + H+
D-glucose 6-phosphate + NADP+
-
-
-
r
D-glucose 6-phosphate + NAD(P)+
6-phospho-D-glucono-1,5-lactone + NAD(P)H + H+
-
-
-
-
?
D-glucose 6-phosphate + NADP+ 2',3'-dialdehyde
6-phospho-D-glucono-1,5-lactone + NADPH 2',3'-dialdehyde + H+
-
-
-
-
?
D-glucose 6-phosphate + thionicotinamide-NAD+
6-phospho-D-glucono-1,5-lactone + thionicotinamide-NADH + H+
-
-
-
-
?
D-glucose 6-phosphate + thionicotinamide-NADP+
6-phospho-D-glucono-1,5-lactone + thionicotinamide-NADPH + H+
-
-
-
-
?
6-phospho-D-gluconate + NAD+
D-ribulose 5-phosphate + CO2 + NADH + H+
-
-
-
?
6-phospho-D-gluconate + NAD+
D-ribulose 5-phosphate + CO2 + NADH + H+
-
-
-
?
6-phospho-D-gluconate + NADP+
D-ribulose 5-phosphate + CO2 + NADPH + H+
-
-
-
?
6-phospho-D-gluconate + NADP+
D-ribulose 5-phosphate + CO2 + NADPH + H+
the enzyme generates NADPH, an essential cofactor for several biosynthetic pathways and antioxidant enzymes
-
-
?
6-phospho-D-gluconate + NADP+
D-ribulose 5-phosphate + CO2 + NADPH + H+
-
-
-
?
6-phospho-D-gluconate + NADP+
D-ribulose 5-phosphate + CO2 + NADPH + H+
the enzyme generates NADPH, an essential cofactor for several biosynthetic pathways and antioxidant enzymes
-
-
?
6-phospho-D-glucono-1,5-lactone + NADH + H+
D-glucose 6-phosphate + NAD+
-
-
-
r
6-phospho-D-glucono-1,5-lactone + NADH + H+
D-glucose 6-phosphate + NAD+
-
-
-
r
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
721400, 721401, 721402, 721406, 721411, 721511, 721570, 721573, 721580, 721584, 722578, 722590, 740878
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
iso ordered bi bi reaction
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
NAD+, NADP+, and pyridoxylation produce different conformational changes in the enzyme
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
steady-state random mechanism
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
the mechanism with NAD+ is more complex compared to the reaction with D-glucose 6-phosphate and NADP+
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
r
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
r
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
721400, 721401, 721402, 721406, 721411, 721511, 721570, 721573, 721580, 721584, 722476, 722578, 722590, 740878
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
NAD+, NADP+, and pyridoxylation produce different conformational changes in the enzyme
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
ordered bi bi reaction
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
ordered, sequential mechanism for this reaction in which NADP+ is bound first to the enzyme and NADPH released last
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
ordered, sequential mechanism. NADP+ binds first
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
r
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
r
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
-
?
additional information
?
-
the reaction catalyzed by PputG6PDH-1 yields around 1/3 mol of NADPH and 2/3 mol of NADH per mol of oxidized glucose 6-phosphate, calculation of in vivo relative production of NADH and NADPH during the oxidation of glucose-6-phosphate. The reaction catalyzes by the 6-phosphogluconate dehydrogenase is active during growth on glucose, and it produces NADPH and NADH. In comparison, for the enzyme of Escherichia coli EcG6PDH, the relative production of NADH over NADPH is 1000times lower than for PputG6PDH-1
-
-
?
additional information
?
-
the reaction catalyzed by PputG6PDH-1 yields around 1/3 mol of NADPH and 2/3 mol of NADH per mol of oxidized glucose 6-phosphate. PputG6PDH-1 is not considered a NADP+-specific enzyme
-
-
?
additional information
?
-
the reaction catalyzed by PputG6PDH-1 yields around 1/3 mol of NADPH and 2/3 mol of NADH per mol of oxidized glucose 6-phosphate, calculation of in vivo relative production of NADH and NADPH during the oxidation of glucose-6-phosphate. The reaction catalyzes by the 6-phosphogluconate dehydrogenase is active during growth on glucose, and it produces NADPH and NADH. In comparison, for the enzyme of Escherichia coli EcG6PDH, the relative production of NADH over NADPH is 1000times lower than for PputG6PDH-1
-
-
?
additional information
?
-
the reaction catalyzed by PputG6PDH-1 yields around 1/3 mol of NADPH and 2/3 mol of NADH per mol of oxidized glucose 6-phosphate. PputG6PDH-1 is not considered a NADP+-specific enzyme
-
-
?
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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
6-phospho-D-gluconate + NAD+
D-ribulose 5-phosphate + CO2 + NADH + H+
-
-
-
?
6-phospho-D-gluconate + NAD+
D-ribulose 5-phosphate + CO2 + NADH + H+
-
-
-
?
6-phospho-D-gluconate + NADP+
D-ribulose 5-phosphate + CO2 + NADPH + H+
the enzyme generates NADPH, an essential cofactor for several biosynthetic pathways and antioxidant enzymes
-
-
?
6-phospho-D-gluconate + NADP+
D-ribulose 5-phosphate + CO2 + NADPH + H+
the enzyme generates NADPH, an essential cofactor for several biosynthetic pathways and antioxidant enzymes
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
r
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
-
?
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
r
D-glucose 6-phosphate + NAD+
6-phospho-D-glucono-1,5-lactone + NADH + H+
-
-
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
r
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
-
?
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
r
D-glucose 6-phosphate + NADP+
6-phospho-D-glucono-1,5-lactone + NADPH + H+
-
-
-
-
?
additional information
?
-
the reaction catalyzed by PputG6PDH-1 yields around 1/3 mol of NADPH and 2/3 mol of NADH per mol of oxidized glucose 6-phosphate, calculation of in vivo relative production of NADH and NADPH during the oxidation of glucose-6-phosphate. The reaction catalyzes by the 6-phosphogluconate dehydrogenase is active during growth on glucose, and it produces NADPH and NADH. In comparison, for the enzyme of Escherichia coli EcG6PDH, the relative production of NADH over NADPH is 1000times lower than for PputG6PDH-1
-
-
?
additional information
?
-
the reaction catalyzed by PputG6PDH-1 yields around 1/3 mol of NADPH and 2/3 mol of NADH per mol of oxidized glucose 6-phosphate, calculation of in vivo relative production of NADH and NADPH during the oxidation of glucose-6-phosphate. The reaction catalyzes by the 6-phosphogluconate dehydrogenase is active during growth on glucose, and it produces NADPH and NADH. In comparison, for the enzyme of Escherichia coli EcG6PDH, the relative production of NADH over NADPH is 1000times lower than for PputG6PDH-1
-
-
?
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COFACTOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
NAD+
kcat/Km of NADP+ is 9.3fold higher compared to kcat/Km of D-glucose 6-phosphate in NAD+-dependent reaction, kcat/Km of D-glucose 6-phosphate in the NADP+-dependent reaction is 3.5fold higher compared to kcat/Km of D-glucose 6-phosphate in NAD+-dependent reaction. kcat/Km of D-glucose 6-phosphate in the NADP+-dependent reaction is 3.5fold higher compared to kcat/Km of D-glucose 6-phosphate in NAD+-dependent reaction
NAD+
-
the maximum quenching of protein fluorescence is 50% for NAD+. The dissociation constant for NAD+ is 2.5 mM
NAD+
-
the mechanism with NAD+ is more complex compared to the reaction with D-glucose 6-phosphate and NADP+
NAD+
the NAD+/enzyme complex is half-open. It is suggested that if NAD+ approaches the open form of the enzyme, and this approach generates a conformation change, initially to the half-open form. The concomitant movement of the coenzyme sheet allows Gln47 to approach the adenine ribose 20-hydroxyl and moves away the side chain of Arg46
NADP+
binds to the furthest open form of the enzyme. Of the residues within the coenzyme domain, only Arg46 moves, interacting with the 20-phosphate and adenine. NAD+ is less well defined in the binding site
NADP+
kcat/Km of NADP+ is 9.3fold higher compared to kcat/Km of D-glucose 6-phosphate in NAD+-dependent reaction, kcat/Km of D-glucose 6-phosphate in the NADP+-dependent reaction is 3.5fold higher compared to kcat/Km of D-glucose 6-phosphate in NAD+-dependent reaction. kcat/Km of D-glucose 6-phosphate in the NADP+-dependent reaction is 3.5fold higher compared to kcat/Km of D-glucose 6-phosphate in NAD+-dependent reaction
NADP+
-
ordered, sequential mechanism for this reaction in which NADP+ is bound first to the enzyme and NADPH released last
NADP+
-
the maximum quenching of protein fluorescence is 5% for NADP+. The dissociation constant for NADP+ is 0.003 mM
NADP+
-
wild-type enzyme prefers NADP+ as coenzyme. Arg46 plays a key role in NADP+-binding
NADP+
-
NAD+-reducing activity is higher than NADP+-reducing activity
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METALS and IONS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
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INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
4-hydroxy-2-nonenal
-
pseudo first-order loss of enzyme activity. The pH dependence of the inactivation rate exhibits an inflection around pH 10, and the enzyme is protected from inactivation by glucose 6-phosphate. Loss of enzyme activity corresponds with the formation of one carbonyl function per enzyme subunit and the appearance of a lysine-4-hydroxy-2-nonenal adduct
cis-9-octadecenoyl-CoA
-
2.0 mM, 9% inhibition of NADP+-dependent reaction, 90% inhibition of NAD+-dependent reaction
citrate
-
incubation of glucose-6-phosphate dehydrogenase from Leuconostoc mesenteroides with Fe2+ and citrate results in rapid O2-dependent inactivation of the enzyme. The Fe(2+)-citrate complex binds to the glucose 6-phosphate binding site and then undergoes reaction with H2O2 formed in solution leading to the oxidative modification of amino acids essential for enzyme activity
CoA
-
3.4 mM, 12% inhibition of NADP+-dependent reaction, 82% inhibition of NAD+-dependent reaction
D-glucose 1-phosphate
-
a substrate-competitive inhibitor, that lowers the dissociation constant and maximum fluorescence quenching for NAD+ but not for NADP+
D-glucose 6-phosphate
-
high concentrations inhibit the NADP+-linked reaction in the dual wavelength assay (a method employing a mixture of one coenzyme and the thionicotinamide analog of the other coenzyme). Such inhibition is not observed in conventional assays using either NADP+ or thionicotinamide-NADP+
Fe3+
-
1 mM, 47.3% loss of activity. 5 mM, 95.2% loss of activity
H2O2
-
the enzyme is rapidly inactivated by micromolar concentrations of Fe2+ and H2O2. Inactivation correlates with the formation of one carbonyl functionality/enzyme subunit, indicating that inactivation is the result of site-specific oxidative modification. Fe2+ binds to the glucose 6-phosphate binding site and interaction of the enzyme-bound Fe2+ with H2O2 leads to the oxidative modification of amino acids essential for enzyme activity. Partially inactivated enzyme remains predominantly in the dimeric form, and no change in the apparent affinity of the remaining active subunits for substrate is observed. Partial inactivation leads to a decrease in the thermal stability of the remaining activity. This decrease in thermal stability could be largely overcome by the addition of glucose 6-phosphate. Thus, although exposure to H2O2 and Fe2+ results in the irreversible inactivation of the enzyme, the resulting modification is selective, leads to the formation of heterodimers of both active and inactive subunits, and does not appear to cause large scale structural changes
malonyl-CoA
-
2.4 mM, no inhibition of NADP+-dependent reaction, 14% inhibition of NAD+-dependent reaction
NADP+ 2',3'-dialdehyde
-
irreversible inactivation in absence of substrate. The inactivation is first order with respect to NADP+ concentration and follows saturation kinetics, indicating that the enzyme initially forms a reversible complex with the inhibitor followed by covalent modification. NADP+ and NAD+ protect the enzyme from inactivation. One molecule of NADP+ 2',3'-dialdehyde binds per subunit of glucose-6-phosphate dehydrogenase when the enzyme is completely inactivated
palmitoyl-CoA
-
inhibition is greatly diminished at high glucose 6-phosphate concentration
pyridoxal 5'-diphospho-5'-adenosine
-
inhibits competitively with respect to glucose 6-phosphate and noncompetitively with respect to NAD+ or NADP+. 0.85 mol of pyridoxal 5'-diphospho-5'-adenosine is required for complete inactivation. Lys21 and Lys343 are the sites of pyridoxal 5'-diphospho-5'-adenosine interaction. Both glucose 6-phosphate and NAD+ protect both lysyl residues against this covalent modification
vanadate
-
inhibition by vanadate dimer and tetramer. The inhibition by vanadate is competitive with respect to NAD+ or NADP+ and noncompetitive (a mixed type) with respect to glucose 6-phosphate when NAD+ or NADP+ are cofactors. The vanadate dimer is the major inhibiting species with respect to NADP+. The vanadate tetramer is the major inhibiting species with respect to glucose 6-phosphate and with respect to NAD+. No inhibition by monomeric vanadate
additional information
-
no inhibition by iodoacetate, iodoacetamide, and p-hydroxymercuribenzoate
-
acetyl-CoA
-
inhibition is greatly diminished at high glucose 6-phosphate concentration
acetyl-CoA
-
2.6 mM, no inhibition of NADP+-dependent reaction, 70% inhibition of NAD+-dependent reaction
ATP
-
inhibition is greatly diminished at high glucose 6-phosphate concentration
ATP
-
the kinetics of ATP inhibition of the NAD+- and NADP+-linked reactions examined at pH 6.2 and pH 7.8. The results are interpreted in terms of ATP addition to binary enzyme-coenzyme and enzyme-glucose 6-phosphate complexes
ATP
-
3.9 mM, 50% inhibition of NADP+-dependent reaction, 90% inhibition of NAD+-dependent reaction
Fe2+
-
incubation of glucose-6-phosphate dehydrogenase from Leuconostoc mesenteroides with Fe2+ and citrate results in rapid O2-dependent inactivation of the enzyme. The Fe(2+)-citrate complex binds to the glucose 6-phosphate binding site and then undergoes reaction with H2O2 formed in solution leading to the oxidative modification of amino acids essential for enzyme activity
Fe2+
-
the enzyme is rapidly inactivated by micromolar concentrations of Fe2+ and H2O2. Inactivation correlates with the formation of one carbonyl functionality/enzyme subunit, indicating that inactivation is the result of site-specific oxidative modification. Fe2+ binds to the glucose 6-phosphate binding site and interaction of the enzyme-bound Fe2+ with H2O2 leads to the oxidative modification of amino acids essential for enzyme activity. Partially inactivated enzyme remains predominantly in the dimeric form, and no change in the apparent affinity of the remaining active subunits for substrate is observed. Partial inactivation leads to a decrease in the thermal stability of the remaining activity. This decrease in thermal stability could be largely overcome by the addition of glucose 6-phosphate. Thus, although exposure to H2O2 and Fe2+ results in the irreversible inactivation of the enzyme, the resulting modification is selective, leads to the formation of heterodimers of both active and inactive subunits, and does not appear to cause large scale structural changes
NADH
-
product inhibition. With NAD+ as the varied substrate and glucose 6-phosphate, nonsaturating, linear noncompetitive inhibition is observed. When an experiment is performed using saturating glucose 6-phosphate, the inhibition again appears to be noncompetitive. When glucose 6-phosphate is the varied substrate inhibition by NADH appears to be noncompetitive whether NAD+ is nonsaturating or saturating
NADH
-
inhibits noncompetitively with respect to thionicotinamide-NAD+
NADP+
-
increasing NADPH/NADP+ concentration ratios inhibit the NADP-linked, but stimulate the NAD-linked reaction
NADPH
-
increasing NADPH/NADP+ concentration ratios inhibit the NADP-linked, but stimulate the NAD-linked reaction
NADPH
-
NADPH is tested as an alternate product inhibitor for the NAD+-linked reaction. With glucose 6-phosphate saturating and NAD+ varied the inhibition is linear noncompetitive
NADPH
-
inhibits competitively with respect to thionicotinamide-NADP+
NADPH
inhibits competitively when NADP+ is the varying substrate and noncompetitively when D-glucose 6-phosphate is the varying substrate
pyridoxal 5'-phosphate
-
inhibition in phosphate buffers at pH 7.7 and pH 6.3. 0.1 mM Pyridoxal 5-phosphate produces 50% inhibition at pH 7.7. At the lower pH more pyridoxal 5-phosphate is required to give the same degree of inhibition. The enzyme must be incubated with pyridoxal 5-phosphate prior to assaying in order to achieve maximum inhibition. Pyridoxamine 5-phosphate and pyridoxal are only slightly inhibitory. When glucose 6-phosphate is varied at a constant, nearly saturating concentration of NAD+ pyridoxal 5-phosphate behaves like a competitive inhibitor. When NAD+ is varied and glucose 6-phosphate maintained at nearly saturating concentration, inhibition by pyridoxal 5-phosphate is noncompetitive
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ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
NADP+
-
increasing NADPH/NADP+ concentration ratios inhibit the NADP-linked, but stimulate the NAD-linked reaction
NADPH
-
increasing NADPH/NADP+ concentration ratios inhibit the NADP-linked, but stimulate the NAD-linked reaction
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DISEASE
TITLE OF PUBLICATION
LINK TO PUBMED
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KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.007
D-glucose 6-phosphate
-
pH 7.8, 25°C, cosubstrate: thionicotinamide-NAD+
0.009
D-glucose 6-phosphate
-
pH 7.8, 25°C, cosubstrate: thionicotinamide-NADP+
0.063
D-glucose 6-phosphate
-
25°C, pH 7.8, cosubstrate: NAD+, mutant enzyme Y415F
0.069
D-glucose 6-phosphate
25°C, pH 7.6, cosubstrate: NAD+, wild-type enzyme
0.0692
D-glucose 6-phosphate
-
wild type enzyme, with NAD+ as cosubstrate, in 33 mM Tris-HCl, pH 7.6, at 25°C
0.074
D-glucose 6-phosphate
-
25°C, pH 7.8, cosubstrate: NADP+, mutant enzyme Y415F
0.075
D-glucose 6-phosphate
-
25°C, pH 7.8, cosubstrate: NAD+, mutant enzyme T14S
0.075
D-glucose 6-phosphate
-
25°C, pH 7.8, cosubstrate: NADP+, mutant enzyme Q47A
0.078
D-glucose 6-phosphate
-
25°C, pH 7.8, NAD+-dependent reaction
0.0891
D-glucose 6-phosphate
-
mutant enzyme R46Q, with NAD+ as cosubstrate, in 33 mM Tris-HCl, pH 7.6, at 25°C
0.09
D-glucose 6-phosphate
-
25°C, pH 7.8, NADP+-dependent reaction
0.096
D-glucose 6-phosphate
-
25°C, pH 7.8, cosubstrate: NAD+, mutant enzyme Q47A
0.097
D-glucose 6-phosphate
25°C, pH 7.6, cosubstrate: NAD+, mutant enzyme K21R
0.114
D-glucose 6-phosphate
25°C, pH 7.6, cosubstrate: NADP+, wild-type enzyme
0.114
D-glucose 6-phosphate
-
wild type enzyme, with NADP+ as cosubstrate, in 33 mM Tris-HCl, pH 7.6, at 25°C
0.117
D-glucose 6-phosphate
-
25°C, pH 7.6, cosubstrate: NADP+, mutant enzyme D177N
0.118
D-glucose 6-phosphate
-
25°C, pH 7.8, cosubstrate: NADP+, mutant enzyme T14S
0.13
D-glucose 6-phosphate
-
20°C, NADP+-linked reaction, pH not specified in the publication
0.132
D-glucose 6-phosphate
-
25°C, pH 7.8, cosubstrate: NAD+, mutant enzyme R46E
0.135
D-glucose 6-phosphate
-
25°C, pH 7.8, cosubstrate: NAD+, mutant enzyme D374Q
0.145
D-glucose 6-phosphate
-
30°C, NADP+-linked reaction, pH not specified in the publication
0.165
D-glucose 6-phosphate
-
25°C, pH 7.8, cosubstrate: NAD+, mutant enzyme Y179F
0.169
D-glucose 6-phosphate
-
25°C, pH 7.8, cosubstrate: NAD+, mutant enzyme T14A