球形节杆菌C224中产生2-酮基-D-葡萄糖酸的膜结合D-葡萄糖脱氢酶：纯化与特性分析

2-Keto-D-gluconate-yielding membrane-bound D-glucose dehydrogenase from Arthrobacter globiformis C224: purification and characterization.

作者信息

Xue Qing, Wei Zhuan, Sun Wenjing, Cui Fengjie, Yu Silian, Zhou Qiang, Liu Jingze

机构信息

School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China.

Parchn Sodium Isovitamin C Co. Ltd, Dexing 334221, China.

出版信息

Molecules. 2015 Jan 8;20(1):846-62. doi: 10.3390/molecules20010846.

Glucose dehydrogenase (GlcDH) is the rate-limiting catalyst for microbial conversion of glucose to the important organic acid 2-ketogluconic acid (2KGlcA). In this study, a D-glucose dehydrogenase was purified from the industrial 2KGlcA producer Arthrobacter globiformis C224. After four purification steps, the GlcDH was successfully purified over 180 folds and specific activity of 88.1 U/mg. A single protein band of 87 kDa was detected by SDS-PAGE. The purified GlcDH had the broad substrate specificity with the Km values for D-glucose, D-xylose, D-galactose and maltose of 0.21 mM, 0.34 mM, 0.46 mM and 0.59 mM, respectively. The kinetic studies proved that A. globiformis GlcDH followed the ping-pong kinetic mechanism. The GlcDH showed an optimum catalytic activity at pH 5.0 and 45 °C with the stable activity at temperature of 20-40 °C and pH of 6.0-7.0. Organic solvents, metal ions or EDTA could significantly influence the GlcDH activity to different degrees.

葡萄糖脱氢酶（GlcDH）是微生物将葡萄糖转化为重要有机酸2-酮基葡萄糖酸（2KGlcA）的限速催化剂。在本研究中，从工业生产2KGlcA的球形节杆菌C224中纯化出一种D-葡萄糖脱氢酶。经过四个纯化步骤，GlcDH成功纯化了180多倍，比活性为88.1 U/mg。通过SDS-PAGE检测到一条87 kDa的单一蛋白条带。纯化后的GlcDH具有广泛的底物特异性，对D-葡萄糖、D-木糖、D-半乳糖和麦芽糖的Km值分别为0.21 mM、0.34 mM、0.46 mM和0.59 mM。动力学研究证明，球形节杆菌GlcDH遵循乒乓动力学机制。GlcDH在pH 5.0和45°C时表现出最佳催化活性，在20-40°C的温度和6.0-7.0的pH值下具有稳定的活性。有机溶剂、金属离子或EDTA会在不同程度上显著影响GlcDH的活性。