title: Coupling hybridization chain reaction with DNAzyme recycling for enzyme-free and dual amplified sensitive fluorescent detection of methyltransferase activity.
abstract: Aberrant DNA methylation originated from changes in DNA methyltransferase activity can lead to many genetic diseases and tumor types, and the monitoring of methyltransferase activity is thus of great importance in disease diagnosis and drug screening. In this work, by combing hybridization chain reaction (HCR) and metal ion-dependent DNAzyme recycling, we have developed a convenient enzyme-free signal amplification strategy for highly sensitive detection of DNA adenine methyltransferase (Dam MTase) activity and its inhibitors. The Dam MTase-induced methylation and subsequent cleavage of the methylated hairpin DNA probes by DpnI endonuclease lead to the release of ssDNA triggers for HCR formation of many Mg2+-dependent DNAzymes, in which the fluorescently quenched substrate sequences are catalytically and cyclically cleaved by Mg2+to generate remarkably amplified fluorescent signals for highly sensitive detection of Dam MTase at 7.23 × 10-4U/mL. In addition, the inhibition of different drugs to Dam MTase activity can also be evaluated with the developed method. With the advantages of simplicity and significant signal amplification over other common methods, the demonstrated biosensing approach thus offers great potential for highly sensitive detection of various methyltransferases and provides a convenient platform for drug screening for therapeutic applications.
authors.affiliation: School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, PR China. Electronic address: jiangby@cqut.edu.cn.
authors.forename: Bingying
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Yulian
authors.initials: Y
authors.lastname: Wei
authors.affiliation: School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, PR China.
authors.forename: Junqiang
authors.initials: J
authors.lastname: Xu
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. Electronic address: yunatswu@swu.edu.cn.
authors.forename: Yun
authors.initials: Y
authors.lastname: Xiang
mesh_terms: D015374:Biosensing Techniques; D004247:DNA; D019175:DNA Methylation; D021881:DNA, Catalytic / Q000737:chemistry*; D009693:Nucleic Acid Hybridization; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000032:analysis*
chemical_list: D021881:DNA, Catalytic; D004247:DNA; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific)
keywords: DNA methyltransferase; DNAzyme; Fluorescence; Hybridization chain reaction; Signal amplification