title: Electrochemical detection of natural DNA damage induced by in situ peroxidase-generated reactive nitrogen species in DNA layer-by-layer films.
abstract: The NO(2)• radical is one kind of reactive nitrogen species and can be generated by horseradish peroxidase (HRP)-catalyzed oxidation of nitrite (NO(2)(-)) in the presence of hydrogen peroxide (H(2)O(2)) and may cause DNA damage in living system. In the present work, {PDDA/DNA}(4) layer-by-layer (LBL) films assembled with poly(diallyldimethylammonium chloride) (PDDA) and natural double-stranded DNA on electrodes were used to detect DNA damage induced by NO(2)• radicals generated from the HRP+H(2)O(2)+NO(2)(-) incubation system using cyclic voltammetry with Ru(bpy)(3)(2+) as the electroactive catalyst in solution. HRP and DNA were then further assembled into PDDA/DNA/{HRP/DNA}(2) LBL films, and the damage of DNA in the films caused by the NO(2)• radicals produced in situ by incubation of the films with H(2)O(2)+NO(2)(-) solutions was detected electrochemically. When catalase layers were assembled on the surface of PDDA/DNA/{HRP/DNA}(2) films, the DNA damage induced by the H(2)O(2)+NO(2)(-) system was inhibited since the catalase in the films could effectively decompose H(2)O(2), and the NO(2)• radicals could not be generated. This work not only provides a foundation for fabricating electrochemical biosensors in detecting NO(2)•-induced DNA damage, but also offers an in vitro model to simulate the pathway of DNA damage and protection in living process.
authors.affiliation: Department of Chemistry, Beijing Normal University, Beijing 100875, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Hongyun
authors.initials: H
authors.lastname: Liu
authors.forename: Naifei
authors.initials: N
authors.lastname: Hu
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002374:Catalase / Q000737:chemistry; D004247:DNA / Q000737:chemistry; D004249:DNA Damage; D055664:Electrochemical Techniques / Q000295:instrumentation* / Q000379:methods*; D004566:Electrodes; D006735:Horseradish Peroxidase / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D011095:Polyethylenes / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D026361:Reactive Nitrogen Species / Q000737:chemistry*
chemical_list: D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; D026361:Reactive Nitrogen Species; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; D004247:DNA; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D002374:Catalase