Crystallization (Comment) | Organism |
---|---|
recombinant enzyme expressed in Escherichia coli, ammonium sulfate precipitation | Thermus thermophilus |
General Stability | Organism |
---|---|
complete loss of activity in presence of 4 M urea | Thermus thermophilus |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
1,2-Cyclohexanediamine-N,N,N',N'-tetraacetate | - |
Thermus thermophilus |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.08 | - |
threo-Ds-3-Isopropylmalate | 60°C | Thermus thermophilus | |
0.63 | - |
NAD+ | 60°C | Thermus thermophilus |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
K+ | in 1.1 M potassium phosphate buffer, pH 7.6, the activity is over 20times that in 0.1 M sodium phosphate. Optimal KCl concentration is above 2 M, enhances activity 20times | Thermus thermophilus | |
Mg2+ | divalent cation required, most active in presence of 0.1 mM Mn2+ or 1 mM Mg2+ | Thermus thermophilus | |
Mn2+ | divalent cation required, most active in presence of 0.1 mM Mn2+ or 1 mM Mg2+ | Thermus thermophilus | |
NH4+ | NH4Cl, optimal concentration is about 0.4 M, enhances activity 18times | Thermus thermophilus | |
Rb+ | RbCl enhances activity | Thermus thermophilus |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Thermus thermophilus | - |
- |
- |
Purification (Comment) | Organism |
---|---|
gene cloned in Escherichia coli | Thermus thermophilus |
Renatured (Comment) | Organism |
---|---|
enzyme solution containing 3.2 M urea is diluted 10times with a urea-free buffer. In samples containing 0.2 mM MnCl2 the activity is restored to 55-60%, full activity is recovered in absence of MnCl2 | Thermus thermophilus |
Storage Stability | Organism |
---|---|
-20°C, stable for at least 6 months when frozen quickly, 40% inactivation when frozen slowly | Thermus thermophilus |
4°C , 50 mM potassium phosphate buffer pH 7.6, 0.5 mM EDTA, 6 months, stable | Thermus thermophilus |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
(2R,3S)-3-isopropylmalate + NAD+ | - |
Thermus thermophilus | 2-oxoisocaproate + NADH + H+ + CO2 | - |
? |
Subunits | Comment | Organism |
---|---|---|
dimer | 2 * 35000-40000, SDS-PAGE | Thermus thermophilus |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
additional information | - |
high concentrations of KCl considerably protect the enzyme from irreversible thermal denaturation | Thermus thermophilus |
87 | - |
denaturation temperature is higher than 87°C | Thermus thermophilus |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.2 | - |
at 75°C, in presence of K+ | Thermus thermophilus |
9 | - |
75°C, without K+ | Thermus thermophilus |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
NAD+ | - |
Thermus thermophilus |