QUINOPROTEIN GLUCOSE-DEHYDROGENASE AND ITS APPLICATION IN AN AMPEROMETRIC GLUCOSE SENSOR
QUINOPROTEIN GLUCOSE-DEHYDROGENASE AND ITS APPLICATION IN AN AMPEROMETRIC GLUCOSE SENSOR
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DOI：
10.1016/0265-928x(86)80011-6
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发表时间：
1986-01-01
期刊：
影响因子：
--
通讯作者：
TURNER, APF
中科院分区：
文献类型：
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作者：
DCOSTA, EJ;HIGGINS, IJ;TURNER, APF
葡萄糖脱氢酶是从醋酸钙不动杆菌LMD 79.41中分离纯化并固定在1，1‘-二甲基二茂铁修饰的石墨箔电极上的一种新近发现的不依赖NAD(P)的氧化还原酶。用直流循环伏安法测定了二茂铁单甲酸(FMCA)在均相体系中电子转移的二级速率常数(Ks)为9.4倍。106L摩尔-1 S。在相同条件下，GDH的Ks值是黄素蛋白葡萄糖氧化酶(GOD)的Ks值的40多倍。在不溶于水的二茂铁衍生物存在下固定化GDH时，也观察到如此高的催化活性；基于GDH的生物传感器被发现产生的电流密度是类似GOD电极的两倍以上。由于增加酶负载量的方法将葡萄糖的检测上限从5 mM提高到15 mM，因此GDH型电极产生的稳态电流受到酶反应的限制。基于葡萄糖脱氢酶的葡萄糖传感器的温度、pH、稳定性和响应特性说明了其在各种实际应用中的潜在用途。特别是，这种生物传感器的高催化活性和对氧的不敏感使其适合于糖尿病治疗中的在体血糖监测。
Glucose dehydrogenase (GDH), one of the recently discovered NAD (P)+-independent ''quinoprotein'' class of oxidoreductase enzymes, was purified from Acinetobacter calcoaceticus LMD 79.41 and immobilised on a 1,1''-dimethylferrocene-modified graphite foil electrode. The second-order rate constant (Ks) for the transfer of electrons between GDH and ferrocenemonocarboxylic acid (FMCA) in a homogeneous system, determined using direct current (DC) cyclic voltammetry, was found to be 9.4 .times. 106 litres mol-1 s-1. This value of ks for GDH was more than 40 times greater than that for the flavoprotein glucose oxidase (GOD) under identical conditions. Such high catalytic activities were also observed when GDH was immobilised in the presence of an insoluble ferrocene derivative; a biosensor based on GDH was found to produce more than twice the current density of similar GOD based electrodes. The steady-state current produced by the GDH-based electrode was limited by the enzymic reaction since methods which increased the enzyme loadings elevated the upper limit of glucose detection from 5 mM to 15 mM. The temperature, pH, stability and response characteristics of the GDH-based glucose sensor illustrate its potential usefulness for a variety of practical applications. In particular, the high catalytic activity and oxygen insensitivity of this biosensor make it suitable for in vivo blood glucose monitoring in the management of diabetes.