title: Sensitive electrochemical assaying of DNA methyltransferase activity based on mimic-hybridization chain reaction amplified strategy.
abstract: A mimic-hybridization chain reaction (mimic-HCR) amplified strategy was proposed for sensitive electrochemically detection of DNA methylation and methyltransferase (MTase) activity In the presence of methylated DNA, DNA-gold nanoparticles (DNA-AuNPs) were captured on the electrode by sandwich-type assembly. It then triggered mimic-HCR of two hairpin probes to produce many long double-helix chains for numerous hexaammineruthenium (III) chloride ([Ru(NH3)6](3+), RuHex) inserting. As a result, the signal for electrochemically detection of DNA MTase activity could be amplified. If DNA was non-methylated, however, the sandwich-type assembly would not form because the short double-stranded DNAs (dsDNA) on the Au electrode could be cleaved and digested by restriction endonuclease HpaII (HapII) and exonuclease III (Exo III), resulting in the signal decrement. Based on this, an electrochemical approach for detection of M.SssI MTase activity with high sensitivity was developed. The linear range for M.SssI MTase activity was from 0.05 U mL(-1) to 10 U mL(-1), with a detection limit down to 0.03 U mL(-1). Moreover, this detecting strategy held great promise as an easy-to-use and highly sensitive method for other MTase activity and inhibition detection by exchanging the corresponding DNA sequence.
authors: Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, PR China; Center for Analysis and Testing, Nanjing Normal University, Nanjing, 210023, PR China.
authors: Linqun
authors: L
authors: Zhang
authors: Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, PR China.
authors: Yuanjian
authors: Y
authors: Liu
authors: Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, PR China.
authors: Ying
authors: Y
authors: Li
authors: Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, PR China.
authors: Yuewu
authors: Y
authors: Zhao
authors: Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, PR China. Electronic address: weiw@seu.edu.cn.
authors: Wei
authors: W
authors: Wei
authors: Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, PR China. Electronic address: liusq@seu.edu.cn.
authors: Songqin
authors: S
authors: Liu
mesh_terms: D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism*; D055664:Electrochemical Techniques; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D009693:Nucleic Acid Hybridization
chemical_list: D006046:Gold; D004248:DNA (Cytosine-5-)-Methyltransferases
keywords: DNA methyltransferase activity; Differential pulse voltammetry; Mimic-hybridization chain reaction; Signal amplification