title: A superstructure-based electrochemical assay for signal-amplified detection of DNA methyltransferase activity.
abstract: DNA methyltransferase (MTase) activity is highly correlated with the occurrence and development of cancer. This work reports a superstructure-based electrochemical assay for signal-amplified detection of DNA MTase activity using M.SssI as an example. First, low-density coverage of DNA duplexes on the surface of the gold electrode was achieved by immobilized mercaptohexanol, followed by immobilization of DNA duplexes. The duplex can be cleaved by BstUI endonuclease in the absence of DNA superstructures. However, the cleavage is blocked after the DNA is methylated by M.SssI. The DNA superstructures are formed with the addition of helper DNA. By using an electroactive complex, RuHex, which can bind to DNA double strands, the activity of M.SssI can be quantitatively detected by differential pulse voltammetry. Due to the high site-specific cleavage by BstUI and signal amplification by the DNA superstructure, the biosensor can achieve ultrasensitive detection of DNA MTase activity down to 0.025U/mL. The method can be used for evaluation and screening of the inhibitors of MTase, and thus has potential in the discovery of methylation-related anticancer drugs.
authors: Jiangsu Key Laboratory of Biomedical Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, National and Local Joint Engineering Research Center of Biomedical Functional Materials, Nanjing Normal University, Nanjing 210097, PR China; Jiangsu Key Laboratory of New Power Batteries, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097, PR China. Electronic address: zhangh@njnu.edu.cn.
authors: Hui
authors: H
authors: Zhang
authors: Jiangsu Key Laboratory of Biomedical Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, National and Local Joint Engineering Research Center of Biomedical Functional Materials, Nanjing Normal University, Nanjing 210097, PR China; Jiangsu Key Laboratory of New Power Batteries, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097, PR China.
authors: Yin
authors: Y
authors: Yang
authors: Jiangsu Key Laboratory of Biomedical Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, National and Local Joint Engineering Research Center of Biomedical Functional Materials, Nanjing Normal University, Nanjing 210097, PR China; Jiangsu Key Laboratory of New Power Batteries, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097, PR China.
authors: Huilei
authors: H
authors: Dong
authors: Jiangsu Key Laboratory of Biomedical Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, National and Local Joint Engineering Research Center of Biomedical Functional Materials, Nanjing Normal University, Nanjing 210097, PR China; Jiangsu Key Laboratory of New Power Batteries, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097, PR China. Electronic address: cxcai@njnu.edu.cn.
authors: Chenxin
authors: C
authors: Cai
mesh_terms: D000669:Amplifiers, Electronic; D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004247:DNA / Q000032:analysis / Q000737:chemistry*; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000032:analysis* / Q000737:chemistry*; D019175:DNA Methylation; D004789:Enzyme Activation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D004247:DNA; D004248:DNA (Cytosine-5-)-Methyltransferases
keywords: DNA methylation; DNA superstructure; Electroanalysis; Methyltransferase; Restriction endonuclease