Hu Yuwei, Wang Fuan, Lu Chun-Hua, Girsh Julia, Golub Eyal, Willner Itamar
Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904 (Israel).
Chemistry. 2014 Dec 1;20(49):16203-9. doi: 10.1002/chem.201404122. Epub 2014 Oct 13.
Mimicking cellular transformations and signal transduction pathways by means of biocatalytic cascades proceeding in organized media is a scientific challenge. We describe two DNA machines that enable the "ON/OFF" switchable activation and deactivation of three-component biocatalytic cascades. One system consists of a reconfigurable DNA tweezers-type structure, whereas in the second system the catalytic cascade proceeds on a switchable DNA clamp scaffold. The three-component catalytic cascades consist of β-galactosidase (β-Gal), glucose oxidase (GOx), and the K(+) -ion-stabilized hemin-G-quadruplex horseradish peroxidase (HRP)-mimicking DNAzyme. The hemin-G-quadruplex-bridged closed structure of the tweezers or clamp allows the biocatalytic cascades to operate (switched "ON''), whereas separation of the hemin-G-quadruplex by means of 18-crown-6-ether opens the tweezers/clamp structures, thus blocking the catalytic cascade (switched "OFF"). This study is complemented by two-component, switchable biocatalytic cascades composed of GOx and hemin-G-quadruplex assembled on hairpin-bridged DNA tweezers or clamp nanostructures.
通过在有序介质中进行的生物催化级联反应来模拟细胞转化和信号转导途径是一项科学挑战。我们描述了两种DNA机器，它们能够对三组分生物催化级联反应进行“开/关”可切换激活和失活。一个系统由可重构的DNA镊子型结构组成，而在第二个系统中，催化级联反应在可切换的DNA夹支架上进行。三组分催化级联反应由β-半乳糖苷酶（β-Gal）、葡萄糖氧化酶（GOx）和K(+)离子稳定的血红素-G-四链体辣根过氧化物酶（HRP）模拟DNAzyme组成。镊子或夹子的血红素-G-四链体桥接闭合结构使生物催化级联反应能够运行（切换为“开”），而通过18-冠-6-醚分离血红素-G-四链体则打开镊子/夹子结构，从而阻断催化级联反应（切换为“关”）。这项研究得到了由GOx和组装在发夹桥接DNA镊子或夹子纳米结构上的血红素-G-四链体组成的双组分可切换生物催化级联反应的补充。
