Electrochemical detection of natural DNA damage induced by in situ peroxidase-generated reactive nitrogen species in DNA layer-by-layer films

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• 作者：Yan Zhang^a ; ^b ; Hongyun Liu^a ; Naifei Hu^a ; ^{hunaifei@bnu.edu.cn}
• 关键词：DNA damage ; NO2&bull ; radical ; Horseradish peroxidase ; Catalase ; Electrochemical detection
• 刊名：Bioelectrochemistry
• 出版年：2012
• 期刊代码：7_15675394
• 类别：ch
• 出版时间：August, 2012
• 卷：86
• 期：Complete
• 页码：67-71
• 文件大小：384 K

摘要

The NO₂鈥?radical is one kind of reactive nitrogen species and can be generated by horseradish peroxidase (HRP)-catalyzed oxidation of nitrite (NO₂^{鈭?/sup>) in the presence of hydrogen peroxide (H₂O₂) 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 NO₂鈥?radicals generated from the HRP + H₂O₂ + NO₂鈭?/sup> incubation system using cyclic voltammetry with Ru(bpy)₃2 + 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 NO₂鈥?radicals produced in situ by incubation of the films with H₂O₂ + NO₂鈭?/sup> 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 H₂O₂ + NO₂鈭?/sup> system was inhibited since the catalase in the films could effectively decompose H₂O₂, and the NO₂鈥?radicals could not be generated. This work not only provides a foundation for fabricating electrochemical biosensors in detecting NO₂鈥?induced DNA damage, but also offers an in vitro model to simulate the pathway of DNA damage and protection in living process.}