摘要
A heroin-binding DNA G-quadruplex （also known as a heroin aptamer or DNAzyme） has been previously re- ported to be able to enhance the peroxidase activity of heroin. In this work, we described a DNAzyme structure that had an effector-recognizing part appearing as a single stranded DNA linkage flanked by two split G-quadruplex halves. Hybridization of the single stranded part in the enzyme with a perfectly matched DNA strand （effector） formed a rigid DNA duplex between the two G-quadruplex halves and thus efficiently suppressed the enzymatic activity of the G-quadruplex/hemin complex, while the mismatched effector strand was not able to regulate the peroxidase activity effectively. With 2,2＇-azinobis（3-ethylbenzthiazoline）-6-sulfonic acid （ABTS） as an oxidizable substrate, we were able to characterize the formation of the re-engineered G-quadruplex/hemin complex and verify its switchable peroxidase activity. Our results show that the split G-quadruplex is an especially useful module to design low-cost and label-free sensors toward various biologically or environmentally interesting targets.
A heroin-binding DNA G-quadruplex （also known as a heroin aptamer or DNAzyme） has been previously re- ported to be able to enhance the peroxidase activity of heroin. In this work, we described a DNAzyme structure that had an effector-recognizing part appearing as a single stranded DNA linkage flanked by two split G-quadruplex halves. Hybridization of the single stranded part in the enzyme with a perfectly matched DNA strand （effector） formed a rigid DNA duplex between the two G-quadruplex halves and thus efficiently suppressed the enzymatic activity of the G-quadruplex/hemin complex, while the mismatched effector strand was not able to regulate the peroxidase activity effectively. With 2,2＇-azinobis（3-ethylbenzthiazoline）-6-sulfonic acid （ABTS） as an oxidizable substrate, we were able to characterize the formation of the re-engineered G-quadruplex/hemin complex and verify its switchable peroxidase activity. Our results show that the split G-quadruplex is an especially useful module to design low-cost and label-free sensors toward various biologically or environmentally interesting targets.
基金
Acknowledgement This work was supported by National Natural Science Foundation of China （N o. 20605019）, PCSIRT （No IRT0756） and the Natural Science Foundation of Anhui Province Ministry of Education （No. K J20 1 2B 169）.
