Riklin A, Katz E, Willner I, Stocker A, Bückmann A F
Institute of Chemistry, Hebrew University of Jerusalem, Israel.
Nature. 1995 Aug 24;376(6542):672-5. doi: 10.1038/376672a0.
Efficient electron transfer of redox proteins to and from their environment is essential for the use of such proteins in biotechnological applications such as amperometric biosensors and photosynthetic biocatalysts. But most redox enzymes lack pathways that can transport an electron from their embedded redox site to an electrode or a diffusing photoexcited species. Electrical communication between redox proteins and electrode surfaces has been improved by aligning proteins on chemically modified electrodes, by attaching electron-transporting groups and by immobilizing proteins in polymer matrices tethered by redox groups. Generally these methods involve contacting the enzymes at random with electron relay units. Here we report an approach that allows site-specific positioning of electron-mediating units in redox proteins. We strip glucose oxidase of its flavin adenine dinucleotide (FAD) cofactors, modify the latter with redox-active ferrocene-containing groups, and then reconstitute the apoprotein with these modified cofactors. In this way, electrical contact between an electrode and the resulting enzyme in solution is greatly enhanced in a controlled and reproducible way.
氧化还原蛋白与其周围环境之间高效的电子转移对于在诸如电流型生物传感器和光合生物催化剂等生物技术应用中使用此类蛋白至关重要。但是大多数氧化还原酶缺乏能够将电子从其嵌入的氧化还原位点传输到电极或扩散的光激发物种的途径。通过在化学修饰电极上排列蛋白质、连接电子传输基团以及将蛋白质固定在由氧化还原基团连接的聚合物基质中，氧化还原蛋白与电极表面之间的电通讯得到了改善。通常，这些方法涉及使酶与电子中继单元随机接触。在此，我们报告了一种能够在氧化还原蛋白中实现电子介导单元位点特异性定位的方法。我们去除葡萄糖氧化酶的黄素腺嘌呤二核苷酸（FAD）辅因子，用含氧化还原活性二茂铁的基团对其进行修饰，然后用这些修饰后的辅因子重构脱辅基蛋白。通过这种方式，电极与溶液中所得酶之间的电接触以可控且可重复的方式得到了极大增强。
