Extended-Range Glucose Sensor Employing Engineered Glucose Dehydrogenases

详细信息    查看全文

• 作者：Tomohiko Yamazaki ; Katsuhiro Kojima ; and Koji Sode
• 刊名：Analytical Chemistry
• 出版年：2000
• 出版时间：October 1, 2000
• 年：2000
• 卷：72
• 期：19
• 页码：4689 - 4693
• 全文大小：78K
• 年卷期：v.72,no.19(October 1, 2000)
• ISSN：1520-6882

文摘

An enzyme glucose sensor with an expanded dynamicrange was constructed using a novel strategy. This strategywas based on a new concept of utilizing protein-engineered enzymes with a different Michaelis constant, whichallows for the expanded dynamic range. We used the engineered Escherichia coli pyrroloquinoline quinone glucose dehydrogenase (PQQGDH) of which His775 wassubstituted for Asp which showed an increased K_m value(25-fold). We first constructed the composite colorimetricanalytical system employing the wild-type PQQGDH andHis775Asp and evaluated its dynamic range. The composite colorimetric analytical system was constructed andshowed a wide dynamic range of 0.5-30 mM with lessthan ±5% error. The composite colorimetric analytical system, an extended-range colorimetric analytical system,enabled the determination of the concentration of glucoseover a 30-fold range that could not have been achievedusing the single colorimetric analytical system. Furthermore, we have demonstrated the composite amperometricglucose sensor employing the combination of His775Asnand His775Asp. The extended-range glucose sensoracquired not only the expanded dynamic range (3-70mM) that covered both dynamic ranges of the singleenzyme sensors but also the narrower substrate specificityof glucose due to the inherited property of engineeredenzymes.