Literature summary for 4.1.1.15 extracted from
Dinh, T.; Ho, N.; Kang, T.; Mcdonald, K.; Won, K.
Salt-free production of gamma-aminobutyric acid from glutamate using glutamate decarboxylase separated from Escherichia coli (2014), J. Chem. Technol. Biotechnol., 89, 1432-1436 .
No PubMed abstract available
Activating Compound
Activating Compound |
Comment |
Organism |
Structure |
additional information |
when commercial cation-exchange resins as solid acids, Amberlyst 15 and Amberlite IRC86, are simply added to the reaction medium, the conversion improves from 13% to 67% without salt formation. Even when water is used as the reaction medium, acidic ion-exchange resins enhance the reaction conversion significantly |
Escherichia coli |
|
Cloned(Commentary)
Cloned (Comment) |
Organism |
gene gadB, recombinant expression in Escherichia coli strain BL21(DE3), subcloning in Escherichia coli strain DH5alpha |
Escherichia coli |
Protein Variants
Protein Variants |
Comment |
Organism |
additional information |
GABA is produced from glutamate through decarboxylation catalyzed by the recombinant glutamate decarboxylase (GAD) expressed in Escherichia coli strain BL21(DE3), the GAD-catalyzed reaction is conducted in 0.2 mol/l sodium acetate buffer (pH 4.6) with 1 mol/l monosodium glutamate at 37°C, optimization of GABA production method, overview. When commercial cation-exchange resins as solid acids are simply added to the reaction medium, the conversion improves from 13% to 67% without salt formation. Even when water is used as the reaction medium, acidic ion-exchange resins enhance the reaction conversion significantly. In a salt-free manner, acidic resins suppress the pH rise during the reaction so that they can enhance the reaction conversion. In addition, they can be recovered and reused easily after the reaction. Heterogeneous solid acids make the GABA production processmore economical and eco-friendly |
Escherichia coli |
Natural Substrates/ Products (Substrates)
Natural Substrates |
Organism |
Comment (Nat. Sub.) |
Natural Products |
Comment (Nat. Pro.) |
Rev. |
Reac. |
L-glutamate |
Escherichia coli |
- |
4-aminobutanoate + CO2 |
- |
? |
|
Organism
Organism |
UniProt |
Comment |
Textmining |
Escherichia coli |
P69910 |
- |
- |
Substrates and Products (Substrate)
Substrates |
Comment Substrates |
Organism |
Products |
Comment (Products) |
Rev. |
Reac. |
L-glutamate |
- |
Escherichia coli |
4-aminobutanoate + CO2 |
- |
? |
|
Subunits
Subunits |
Comment |
Organism |
homohexamer |
- |
Escherichia coli |
Synonyms
Synonyms |
Comment |
Organism |
GAD |
- |
Escherichia coli |
GadB |
- |
Escherichia coli |
GADbeta |
- |
Escherichia coli |
Temperature Optimum [°C]
Temperature Optimum [°C] |
Temperature Optimum Maximum [°C] |
Comment |
Organism |
37 |
- |
assay at |
Escherichia coli |
pH Optimum
pH Optimum Minimum |
pH Optimum Maximum |
Comment |
Organism |
4.6 |
- |
assay at |
Escherichia coli |
pH Range
pH Minimum |
pH Maximum |
Comment |
Organism |
3.5 |
5.5 |
GAD is active in the range pH 3.5 to pH 5.5 with optimal pH at 4.6, inactive above pH 6.0 |
Escherichia coli |
Cofactor
Cofactor |
Comment |
Organism |
Structure |
pyridoxal 5'-phosphate |
dependent on |
Escherichia coli |
|
General Information
General Information |
Comment |
Organism |
malfunction |
at pH values above pH 6.0, GAD is inactive due to conformational change of the hexameric enzyme at its N- and C-termini from acidic to neutral pH. Especially, His465 at the C-terminus of the enzyme together with Glu89 are demonstrated to be involved in the conformational change in a cooperative manner |
Escherichia coli |