电化学循环放大法检测腺嘌呤甲基转移酶的活性

Detection of DNA methyltransferase Dam activity using the electrochemical techniques based on the recycling DNA chain amplification

DNA甲基转移酶(Dnmt)可以催化DNA的甲基化反应的发生。生物体内DNA异常甲基化可能导致肿瘤的发生和演进。因此,在疾病的治疗和预防中,Dnmt可能成为一个重要的分子靶标。本文以DNA腺嘌呤甲基转移酶(Dam)为研究对象,设计了含-GATC-特定序列的双链DNA和巯基标记及二茂铁基团的两条互补DNA链作为阴阳探针,从Dam和核酸内切酶DpnI的特异性识别作用出发,利用核酸链之间的竞争性杂交实现对甲基转移酶活性的检测,并利用λ核酸外切酶特异性识别作用,构建电化学循环放大检测甲基转移酶活性的新方法来提高检测的灵敏度。

It is well known that DNA methylation is catalyzed and maintained by DNA methyltransferase（Dnmt）.Aberrant DNA methylation is associated with cancer initiation and progression.So Dnmt could be an important therapeutical targets.Here we described a sensitive approach for DNA adenine methyltransferase（Dam）activity assay on DNA modified electrodes based on the probe of double-strand DNA（dsDNA）,which contained the specific sequence of-GATC-with sulfhydryl or ferrocene-based group.The recycling amplification could be triggered by lambda exonuclease.