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Pyridoxine Supplementation Improves the Activity of Recombinant Glutamate Decarboxylase and the Enzymatic Production of Gama-Aminobutyric Acid.
- Source :
-
PloS one [PLoS One] 2016 Jul 20; Vol. 11 (7), pp. e0157466. Date of Electronic Publication: 2016 Jul 20 (Print Publication: 2016). - Publication Year :
- 2016
-
Abstract
- Glutamate decarboxylase (GAD) catalyzes the irreversible decarboxylation of L-glutamate to the valuable food supplement γ-aminobutyric acid (GABA). In this study, GAD from Escherichia coli K12, a pyridoxal phosphate (PLP)-dependent enzyme, was overexpressed in E. coli. The GAD produced in media supplemented with 0.05 mM soluble vitamin B6 analog pyridoxine hydrochloride (GAD-V) activity was 154.8 U mL-1, 1.8-fold higher than that of GAD obtained without supplementation (GAD-C). Purified GAD-V exhibited increased activity (193.4 U mg-1, 1.5-fold higher than that of GAD-C), superior thermostability (2.8-fold greater than that of GAD-C), and higher kcat/Km (1.6-fold higher than that of GAD-C). Under optimal conditions in reactions mixtures lacking added PLP, crude GAD-V converted 500 g L-1 monosodium glutamate (MSG) to GABA with a yield of 100%, and 750 g L-1 MSG with a yield of 88.7%. These results establish the utility of pyridoxine supplementation and lay the foundation for large-scale enzymatic production of GABA.
Details
- Language :
- English
- ISSN :
- 1932-6203
- Volume :
- 11
- Issue :
- 7
- Database :
- MEDLINE
- Journal :
- PloS one
- Publication Type :
- Academic Journal
- Accession number :
- 27438707
- Full Text :
- https://doi.org/10.1371/journal.pone.0157466