Electrochemical strategy for sensing DNA methylation and DNA methyltransferase activity
Electrochemical strategy for sensing DNA methylation and DNA methyltransferase activity
复制标题
传感 DNA 甲基化和 DNA 甲基转移酶活性的电化学策略
DOI：
10.1016/j.aca.2013.01.026
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发表时间：
2013-03-20
影响因子：
6.2
通讯作者：
Li, Nian Bing
中科院分区：
文献类型：
--
作者：
Wang, Gang Lin;Zhou, Long Yin;Li, Nian Bing
The present work demonstrates a novel signal-off electrochemical method for the determination of DNA methylation and the assay of methyltransferase activity using the electroactive complex [Ru(NH3)(6)](3+) (RuHex) as a signal transducer. The assay exploits the electrostatic interactions between RuHex and DNA strands. Thiolated single strand DNA1 was firstly self-assembled on a gold electrode via Au-S bonding, followed by hybridization with single strand DNA2 to form double strand DNA containing specific recognition sequence of DNA adenine methylation MTase and methylation-responsive restriction endonuclease Dpn I. The double strand DNA may adsorb lots of electrochemical species (Ru(NH3)(6)](3+)) via the electrostatic interaction, thus resulting in a high electrochemical signal. In the presence of DNA adenine methylation methyltransferase and S-adenosyl-L-methionine, the formed double strand DNA was methylated by DNA adenine methylation methyltransferase, then the double strand DNA can be cleaved by methylation-responsive restriction endonuclease Dpn I, leading to the dissociation of a large amount of signaling probes from the electrode. As a result, the adsorption amount of RuHex reduced, resulting in a decrease in electrochemical signal. Thus, a sensitive electrochemical method for detection of DNA methylation is proposed. The proposed method yielded a linear response to concentration of Dam MTase ranging from 0.25 to IOU mL(-1) with a detection limit of 0.18 U mL(-1) (S/N = 3), which might promise this method as a good candidate for monitoring DNA methylation in the future. (C) 2013 Elsevier B.V. All rights reserved.
