Cloning, expression and characterization of a glucose dehydrogenase from Bacillus sp G3 in Escherichia coli
Cloning, expression and characterization of a glucose dehydrogenase from Bacillus sp G3 in Escherichia coli
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大肠杆菌中芽孢杆菌 G3 葡萄糖脱氢酶的克隆、表达和表征
DOI：
10.5897/ajmr11.831
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发表时间：
2011-12-30
影响因子：
--
通讯作者：
Zhao, Yuhua
中科院分区：
文献类型：
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作者：
Chen, Xuejiao;Ding, Haitao;Zhao, Yuhua
从芽孢杆菌G3中克隆到葡萄糖脱氢酶基因（gdh），该基因全长786 bp，推测蛋白质分子量为28.1kDa。重组葡萄糖脱氢酶（rGDH-G3）在大肠杆菌中得到了功能性表达。结果表明，表达的rGDH-G3在25 ℃和pH 8.0下具有371.9 U/mg的高比活性，氧化烟酰胺腺嘌呤二核苷酸（NAD（+））为辅因子。该酶在40 ℃和pH 9.0下具有最佳活性。该酶对其他糖如D-半乳糖或麦芽糖具有广泛的特异性。当用氧化型烟酰胺腺嘌呤二核苷酸磷酸（NADP（+））代替NAD（+）作为辅因子时，rGDH-G3的催化效率可提高4倍。
The glucose dehydrogenase gene (gdh), cloned from Bacillus sp. G3, was composed of 786 bp nucleotide and the deduced protein molecular mass of one subunit was 28.1 kDa. The recombinant glucose dehydrogenase (rGDH-G3) was functionally expressed in Escherichia coli. The results revealed that expressed rGDH-G3 had a high specific activity of 371.9 U/mg at 25 degrees C and pH 8.0, with oxidized nicotinamide adenine dinucleotide (NAD(+)) as the cofactor. The enzyme was optimally active at 40 degrees C and pH 9.0. The enzyme displayed broad specificity for other sugars such as D-galactose or maltose. The catalytic efficiency of the rGDH-G3 would be improved 4 times when oxidized nicotinamide adenine dinucleotide phosphate (NADP(+)) was used as cofactor instead of NAD(+).