Piperberg Gilad, Wilner Ofer I, Yehezkeli Omer, Tel-Vered Ran, Willner Itamar
Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
J Am Chem Soc. 2009 Jul 1;131(25):8724-5. doi: 10.1021/ja900718m.
The spatial organization of biomolecules on a DNA scaffold linked to an electrode leads to programmed biocatalytic transformations. This is exemplified by the electrical contacting of glucose oxidase (GOx) linked to the DNA scaffold with the electrode. A nucleic acid functionalized with a ferrocene relay unit was hybridized with the DNA scaffold at a position adjacent to the electrode, and GOx functionalized with nucleic acid units complementary to the specific domain of the DNA template was hybridized with the DNA scaffold in a position remote from the electrode. Under these conditions, ferrocene-mediated oxidation of the redox center of GOx occurred, and the effective bioelectrocatalytic oxidation of glucose was activated. Exchange of the position of GOx and the electron-mediator groups prohibited the bioelectrocatalytic oxidation of glucose. In another system, a nucleic acid-functionalized microperoxidase-11 (MP-11) and the nucleic acid-modified GOx were hybridized with the adjacent and remote sites, respectively, on the DNA scaffold associated with the electrode. In this configuration, effective MP-11-catalyzed reduction of H(2)O(2) generated by the GOx-catalyzed oxidation of glucose occurred, and the resulting bioelectrocatalytic cathodic currents were controlled by the concentration of glucose. Exchanging the positions of MP-11 and GOx on the DNA scaffold eliminated the MP-11-electrocatalyzed reduction of H(2)O(2).
连接到电极的DNA支架上生物分子的空间组织导致了程序化的生物催化转化。以连接到DNA支架上的葡萄糖氧化酶（GOx）与电极的电接触为例。用二茂铁中继单元功能化的核酸在与电极相邻的位置与DNA支架杂交，而用与DNA模板特定结构域互补的核酸单元功能化的GOx在远离电极的位置与DNA支架杂交。在这些条件下，发生了二茂铁介导的GOx氧化还原中心的氧化，葡萄糖的有效生物电催化氧化被激活。GOx和电子介导基团位置的交换阻止了葡萄糖的生物电催化氧化。在另一个系统中，核酸功能化的微过氧化物酶-11（MP-11）和核酸修饰的GOx分别与连接到电极的DNA支架上的相邻和远离位点杂交。在这种配置下，发生了由GOx催化葡萄糖氧化产生的H(2)O(2)的有效MP-11催化还原，并且由此产生的生物电催化阴极电流受葡萄糖浓度的控制。在DNA支架上交换MP-11和GOx的位置消除了MP-11对H(2)O(2)的电催化还原。
