Runqiang Yang, Yongqi Yin, Qianghui Guo, Zhenxin Gu
College of Food Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
Food chemistry 2013 Jun 1Gamma-aminobutyric acid (GABA) is a non-protein amino acid with bioactive functions in humans. In this work, glutamate decarboxylase (EC 4.1.1.15, GAD) which is key in the GABA bioformation was purified from 5-day germinated faba beans and characterized. A single band was observed at 58 kDa using sodium dodecyl sulphate gel electrophoresis. GAD optimal activity was at pH 6.0 at 40°C with a K(m) value for glutamic acid (Glu) of 2.63 mM. The enzyme was inhibited significantly by Cu(2+), Fe(3+), Mg(2+), Ba(2+), aminoxyacetate, EGTA, Na(2)EDTA, l-cysteine and beta-mercaptoethanol; and activated at low Ca(2+) 0.2mM. Using RT-PCR, the GAD cDNA was sequenced which indicated 1787 bp long, containing a 1527 bp open reading frame (ORF) that encoded 509 amino-acid peptides with a calculated molecular weight of 57.74 kDa and a pI of 5.41 (GenBank accession number: JX444699). Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.
Runqiang Yang, Yongqi Yin, Qianghui Guo, Zhenxin Gu. Purification, properties and cDNA cloning of glutamate decarboxylase in germinated faba bean (Vicia faba L.). Food chemistry. 2013 Jun 1;138(2-3):1945-51
PMID: 23411329
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