title: A sensitive signal-on assay for MTase activity based on methylation-responsive hairpin-capture DNA probe.
abstract: This work develops a simple, sensitive and signal-on electrochemical sensor for methyltransferase (MTase) activity analysis. The sensor is composed of a methylene blue-modiﬁed "signaling DNA probe" and a "capture DNA probe" tethered methylation-responsive hairpin DNA (hairpin-capture DNA probe). The thiol- modified hairpin-capture DNA probe at 5' end was firstly self-assembled on gold electrode via Au-S bonding. Methylation-induced scission of hairpin-capture DNA probe would displace the hairpin section and remain the "capture DNA probe" section on the gold electrode. Subsequently, the remained "capture DNA probe" on the gold electrode can hybridize with the methylene blue-modiﬁed "signaling DNA probe", mediating methylene blue onto the gold electrode surface to generate redox current. It was eT on state. The developed facile signal-on electrochemical sensing system showed a linear response to concentration of Dam MTase range from 0.1 to 1.0 U/mL. The detection limit of Dam MTase activity was determined to be 0.07 U/mL and the total detection time is 7h. The sensor also has the ability to provide information about the dynamics of methylation process. Furthermore, we demonstrated that this sensor could be utilized to screen inhibitors or drugs for Dam MTase.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College Hunan University, Changsha 410082, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Su
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: He
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Wang
authors.forename: Kemin
authors.initials: K
authors.lastname: Wang
authors.forename: Zhifeng
authors.initials: Z
authors.lastname: Chen
authors.forename: Genping
authors.initials: G
authors.lastname: Yan
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D019175:DNA Methylation; D015342:DNA Probes / Q000737:chemistry; D004262:DNA Restriction Enzymes / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D005472:Fluorouracil / Q000737:chemistry; D005839:Gentamicins / Q000737:chemistry; D055029:Inverted Repeat Sequences; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D015342:DNA Probes; D005839:Gentamicins; C058693:Dam methyltransferase; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); D004262:DNA Restriction Enzymes; D005472:Fluorouracil