Department of Life Sciences and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev , Beer-Sheva 84105, Israel.
National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev , Beer-Sheva 84105, Israel.
J Am Chem Soc. 2017 Dec 6;139(48):17217-17220. doi: 10.1021/jacs.7b07011. Epub 2017 Sep 21.
Flavin-adenine dinucleotide (FAD) dependent glucose dehydrogenase (GDH) is a thermostable, oxygen insensitive redox enzyme used in bioelectrochemical applications. The FAD cofactor of the enzyme is buried within the proteinaceous matrix of the enzyme, which makes it almost unreachable for a direct communication with an electrode. In this study, FAD dependent glucose dehydrogenase was fused to a natural minimal cytochrome domain in its c-terminus to achieve direct electron transfer. We introduce a fusion enzyme that can communicate with an electrode directly, without the use of a mediator molecule. The new fusion enzyme, with its direct electron transfer abilities displays superior activity to that of the native enzyme, with a k that is ca. 3 times higher than that of the native enzyme, a k/K that is more than 3 times higher than that of GDH and 5 to 7 times higher catalytic currents with an onset potential of ca. (-) 0.15 V vs Ag/AgCl, affording higher glucose sensing selectivity. Taking these parameters into consideration, the fusion enzyme presented can serve as a good candidate for blood glucose monitoring and for other glucose based bioelectrochemical systems.
黄素腺嘌呤二核苷酸（FAD）依赖性葡萄糖脱氢酶（GDH）是一种热稳定、对氧不敏感的氧化还原酶，用于生物电化学应用。该酶的 FAD 辅因子埋藏在酶的蛋白质基质中，这使得它几乎无法与电极进行直接通讯。在这项研究中，FAD 依赖性葡萄糖脱氢酶在其 C 末端与天然最小细胞色素结构域融合，以实现直接电子转移。我们引入了一种融合酶，它可以直接与电极进行通讯，而无需使用介体分子。新的融合酶具有直接电子转移能力，其活性高于天然酶，k 值约为天然酶的 3 倍，k/K 值比 GDH 高 3 倍以上，具有约 -0.15 V （相对于 Ag/AgCl）的起始电位的催化电流高 5 至 7 倍，提供更高的葡萄糖检测选择性。考虑到这些参数，所提出的融合酶可以作为血糖监测和其他基于葡萄糖的生物电化学系统的良好候选物。
