BRENDA - Enzyme Database

Role of alpha-Asp181, beta-Asp192, and gamma-Asp190 in the distinctive subunits of human NAD-specific isocitrate dehydrogenase

Bzymek, K.P.; Colman, R.F.; Biochemistry 46, 5391-5397 (2007)

Data extracted from this reference:

Activating Compound
EC Number
Activating Compound
Commentary
Organism
Structure
1.1.1.41
ADP
activates. Michaelis-Menten constant for DL-isocitrate is lowered 3.5-fold in the wild-type IDH. The substitution of asparagine for aspartate in alpha-mutant enzyme D181N, beta-subunit mutant enzyme D192N, and gamma-subunit mutant enzyme D190N abolishes this allosteric effect of ADP on Km
Homo sapiens
Engineering
EC Number
Amino acid exchange
Commentary
Organism
1.1.1.41
D181N
mutation in the alpha-subunit exhibits a 2000fold decrease in Vmax, with increases of 15fold in the Kms for Mn2+ and NAD+ and a much smaller change in the Km for isocitrate. Mutant enzyme fails to respond to ADP by lowering the Km for isocitrate, although it binds to ADP
Homo sapiens
1.1.1.41
D190N
mutation in the gamma-subunit results in 4-5fold decrease in Vmax as compared to wild-type enzyme. The Km-values for NAD+ and for Mn2+ of the mutant enzyme are 19 and 72 times, respectively, that of the wild-type enzyme with a much smaller effect on the Km for isocitrate. Mutant enzyme fails to respond to ADP by lowering the Km for isocitrate, although it binds to ADP
Homo sapiens
1.1.1.41
D192N
mutation in the beta-subunit results in 4-5fold decrease in Vmax as compared to wild-type enzyme. The Km-value for NAD+ of the mutant enzyme is 9times that of the normal enzyme with little or no effect on the affinity for Mn2+ or isocitrate. Mutant enzyme fails to respond to ADP by lowering the Km for isocitrate, although it binds to ADP
Homo sapiens
KM Value [mM]
EC Number
KM Value [mM]
KM Value Maximum [mM]
Substrate
Commentary
Organism
Structure
1.1.1.41
0.08
-
NAD+
pH 7.2, wild-type enzyme
Homo sapiens
1.1.1.41
0.71
-
NAD+
pH 7.2, beta-subunit mutant enzyme D192N
Homo sapiens
1.1.1.41
1.2
-
NAD+
pH 7.2, alpha-subunit mutant enzyme D181N
Homo sapiens
1.1.1.41
1.5
-
NAD+
pH 7.2, gamma-subunit mutant enzyme D190N
Homo sapiens
1.1.1.41
2.4
-
isocitrate
pH 7.2, wild-type enzyme
Homo sapiens
1.1.1.41
2.9
-
isocitrate
pH 7.2, beta-subunit mutant enzyme D192N
Homo sapiens
1.1.1.41
9.1
-
isocitrate
pH 7.2, alpha-subunit mutant enzyme D181N
Homo sapiens
1.1.1.41
13
-
isocitrate
pH 7.2, gamma-subunit mutant enzyme D190N
Homo sapiens
Metals/Ions
EC Number
Metals/Ions
Commentary
Organism
Structure
1.1.1.41
Mn2+
required. KM-value: 0.067 mM for wild-type enzyme, 1.09 mM for the alpha-subunit mutant D181N, 0.14 mM for the beta-subunit mutant D192N. 4.8 mM for the gamma-subunit mutant D190N
Homo sapiens
Molecular Weight [Da]
EC Number
Molecular Weight [Da]
Molecular Weight Maximum [Da]
Commentary
Organism
1.1.1.41
238000
-
gel filtration
Homo sapiens
Organism
EC Number
Organism
Primary Accession No. (UniProt)
Commentary
Textmining
1.1.1.41
Homo sapiens
-
-
-
Substrates and Products (Substrate)
EC Number
Substrates
Commentary Substrates
Literature (Substrates)
Organism
Products
Commentary (Products)
Literature (Products)
Organism (Products)
Reversibility
1.1.1.41
isocitrate + NAD+
-
685154
Homo sapiens
2-oxoglutarate + CO2 + NADH + H+
-
-
-
?
Subunits
EC Number
Subunits
Commentary
Organism
1.1.1.41
More
the ratios of the alpha-, beta-, and gamma-subunits of the wild-type and three mutant enzymes all approximate 2:1:1
Homo sapiens
Activating Compound (protein specific)
EC Number
Activating Compound
Commentary
Organism
Structure
1.1.1.41
ADP
activates. Michaelis-Menten constant for DL-isocitrate is lowered 3.5-fold in the wild-type IDH. The substitution of asparagine for aspartate in alpha-mutant enzyme D181N, beta-subunit mutant enzyme D192N, and gamma-subunit mutant enzyme D190N abolishes this allosteric effect of ADP on Km
Homo sapiens
Engineering (protein specific)
EC Number
Amino acid exchange
Commentary
Organism
1.1.1.41
D181N
mutation in the alpha-subunit exhibits a 2000fold decrease in Vmax, with increases of 15fold in the Kms for Mn2+ and NAD+ and a much smaller change in the Km for isocitrate. Mutant enzyme fails to respond to ADP by lowering the Km for isocitrate, although it binds to ADP
Homo sapiens
1.1.1.41
D190N
mutation in the gamma-subunit results in 4-5fold decrease in Vmax as compared to wild-type enzyme. The Km-values for NAD+ and for Mn2+ of the mutant enzyme are 19 and 72 times, respectively, that of the wild-type enzyme with a much smaller effect on the Km for isocitrate. Mutant enzyme fails to respond to ADP by lowering the Km for isocitrate, although it binds to ADP
Homo sapiens
1.1.1.41
D192N
mutation in the beta-subunit results in 4-5fold decrease in Vmax as compared to wild-type enzyme. The Km-value for NAD+ of the mutant enzyme is 9times that of the normal enzyme with little or no effect on the affinity for Mn2+ or isocitrate. Mutant enzyme fails to respond to ADP by lowering the Km for isocitrate, although it binds to ADP
Homo sapiens
KM Value [mM] (protein specific)
EC Number
KM Value [mM]
KM Value Maximum [mM]
Substrate
Commentary
Organism
Structure
1.1.1.41
0.08
-
NAD+
pH 7.2, wild-type enzyme
Homo sapiens
1.1.1.41
0.71
-
NAD+
pH 7.2, beta-subunit mutant enzyme D192N
Homo sapiens
1.1.1.41
1.2
-
NAD+
pH 7.2, alpha-subunit mutant enzyme D181N
Homo sapiens
1.1.1.41
1.5
-
NAD+
pH 7.2, gamma-subunit mutant enzyme D190N
Homo sapiens
1.1.1.41
2.4
-
isocitrate
pH 7.2, wild-type enzyme
Homo sapiens
1.1.1.41
2.9
-
isocitrate
pH 7.2, beta-subunit mutant enzyme D192N
Homo sapiens
1.1.1.41
9.1
-
isocitrate
pH 7.2, alpha-subunit mutant enzyme D181N
Homo sapiens
1.1.1.41
13
-
isocitrate
pH 7.2, gamma-subunit mutant enzyme D190N
Homo sapiens
Metals/Ions (protein specific)
EC Number
Metals/Ions
Commentary
Organism
Structure
1.1.1.41
Mn2+
required. KM-value: 0.067 mM for wild-type enzyme, 1.09 mM for the alpha-subunit mutant D181N, 0.14 mM for the beta-subunit mutant D192N. 4.8 mM for the gamma-subunit mutant D190N
Homo sapiens
Molecular Weight [Da] (protein specific)
EC Number
Molecular Weight [Da]
Molecular Weight Maximum [Da]
Commentary
Organism
1.1.1.41
238000
-
gel filtration
Homo sapiens
Substrates and Products (Substrate) (protein specific)
EC Number
Substrates
Commentary Substrates
Literature (Substrates)
Organism
Products
Commentary (Products)
Literature (Products)
Organism (Products)
Reversibility
1.1.1.41
isocitrate + NAD+
-
685154
Homo sapiens
2-oxoglutarate + CO2 + NADH + H+
-
-
-
?
Subunits (protein specific)
EC Number
Subunits
Commentary
Organism
1.1.1.41
More
the ratios of the alpha-, beta-, and gamma-subunits of the wild-type and three mutant enzymes all approximate 2:1:1
Homo sapiens