Department of Biotechnology, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan; Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, 3-8-1 Harumi-cho, Fuchu, Tokyo 183-8538, Japan; Ultizyme International Ltd., 1-13-16, Minami, Meguro, Tokyo 152-0013, Japan.
Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, 3-8-1 Harumi-cho, Fuchu, Tokyo 183-8538, Japan.
Biosens Bioelectron. 2017 Jan 15;87:305-311. doi: 10.1016/j.bios.2016.08.053. Epub 2016 Aug 18.
In this study, a novel fungus FAD dependent glucose dehydrogenase, derived from Aspergillus niger (AnGDH), was characterized. This enzyme's potential for the use as the enzyme for blood glucose monitor enzyme sensor strips was evaluated, especially by investigating the effect of the presence of xylose during glucose measurements. The substrate specificity of AnGDH towards glucose was investigated, and only xylose was found as a competing substrate. The specific catalytic efficiency for xylose compared to glucose was 1.8%. The specific activity of AnGDH for xylose at 5mM concentration compared to glucose was 3.5%. No other sugars were used as substrate by this enzyme. The superior substrate specificity of AnGDH was also demonstrated in the performance of enzyme sensor strips. The impact of spiking xylose in a sample with physiological glucose concentrations on the sensor signals was investigated, and it was found that enzyme sensor strips using AnGDH were not affected at all by 5mM (75mg/dL) xylose. This is the first report of an enzyme sensor strip using a fungus derived FADGDH, which did not show any positive bias at a therapeutic level xylose concentration on the signal for a glucose sample. This clearly indicates the superiority of AnGDH over other conventionally used fungi derived FADGDHs in the application for SMBG sensor strips. The negligible activity of AnGDH towards xylose was also explained on the basis of a 3D structural model, which was compared to the 3D structures of A. flavus derived FADGDH and of two glucose oxidases.
在这项研究中，我们对一种新型的黑曲霉来源的黄素腺嘌呤二核苷酸（FAD）依赖型葡萄糖脱氢酶（AnGDH）进行了研究。评估了该酶作为血糖监测酶传感器条用酶的潜力，特别是通过研究在葡萄糖测量过程中存在木糖时的影响。研究了 AnGDH 对葡萄糖的底物特异性，仅发现木糖是竞争底物。与葡萄糖相比，AnGDH 对木糖的特异性催化效率为 1.8%。与葡萄糖相比，AnGDH 在 5mM 浓度下对木糖的比活性为 3.5%。该酶没有将其他糖用作底物。AnGDH 的优越的底物特异性也在酶传感器条的性能中得到了证明。研究了在生理葡萄糖浓度的样品中添加木糖对传感器信号的影响，结果发现，使用 AnGDH 的酶传感器条完全不受 5mM（75mg/dL）木糖的影响。这是首次报道使用真菌衍生的 FADGDH 的酶传感器条在治疗水平的木糖浓度下对葡萄糖样品的信号没有任何正偏差。这清楚地表明，在用于 SMBG 传感器条的应用中，AnGDH 优于其他常规使用的真菌衍生的 FADGDH。AnGDH 对木糖的可忽略不计的活性也可以根据 3D 结构模型来解释，该模型与黄曲霉衍生的 FADGDH 和两种葡萄糖氧化酶的 3D 结构进行了比较。
