Cloning,Expression,Purification and Characterization of Glutamate Decarboxylase from Lactococcus lactis subsp.lactis IL1403

Abstract:

Glutamate decarboxylase(GAD) is the main enzyme for biotransformation glutamate to gamma-Aminobutyric acid(GABA),a functional factor.In order to obtain a genetically engineered bacteria with high activity of GAD,a gene encoding glutamate decarboxylase from Lactococcus lactis subsp.lactis IL1403 was cloned and over-expressed in Escherichia coli BL21(DE3).The bacterium was induced by IPTG and analyzed by SDS-PAGE.The recombinant glutamate decarboxylase was purified to electrophoretic homogeneity by affinity chromatography.Approximately 54 kDa exogenous proteins were observed on the SDS-PAGE.The activity of recombinant GAD was also studied,the bioconversion rate reached 98.2% after 30 minutes,which was a significant improvement when compared with that of the wild type strain.