A label-free, G-quadruplex DNAzyme-based fluorescent probe for signal-amplified DNA detection and turn-on assay of endonuclease
A label-free, G-quadruplex DNAzyme-based fluorescent probe for signal-amplified DNA detection and turn-on assay of endonuclease
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一种无标记、基于 G-四链体 DNAzyme 的荧光探针，用于信号放大 DNA 检测和核酸内切酶启动测定
DOI：
10.1016/j.bios.2012.01.024
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发表时间：
2012-04-15
影响因子：
12.6
通讯作者：
Dong, Shaojun
中科院分区：
文献类型：
--
作者：
Zhou, Zhixue;Du, Yan;Dong, Shaojun
A novel G-quadruplex DNAzyme molecular beacon (G-DNAzymeMB) strategy is developed for assays of target DNA and restriction endonuclease. The detection system consists of G-DNAzymeMB strand and a blocker DNA by using the fluorescence of 2',7'-dichlorodihydrofluorescein diacetate (H(2)DCFDA) catalyzed by G-DNAzymeMB as a signal reporter. G-DNAzymeMB exhibits peroxidase activity in its free hairpin structure, and forms a catalytically inactive hybrid when hybridized with blocker DNA. Upon displacement of blocker DNA by target DNA or cleavage by restriction endonuclease. G-DNAzymeMB is released and two lateral portions of G-DNAzymeMB form a G-quadruplex structure, resulting in the recovery of catalytic activity which acts as a cofactor to catalyze H2O2-mediated oxidation of H(2)DCFDA. For DNA detection system, exonuclease III (Exo III)-catalyzed amplification strategy is introduced to improve the sensitivity and target DNA could be detected as low as 0.1 pM. With respect to restriction endonuclease detection system, 0.1 U/mL EcoRI endonuclease could be detected and this method could be easily transported to other restriction endonuclease analysis by simply changing the recognition sequence. These results demonstrate that the proposed G-DNAzymeMB strategy could be used as a label-free, simple, sensitive and cost-effective approach in analysis of target DNA and restriction endonuclease. (C) 2012 Elsevier B.V. All rights reserved.
