Electrochemical Detection of Lesions in DNA

详细信息    查看全文

• 作者：Amie K. Boal and Jacqueline K. Barton
• 刊名：Bioconjugate Chemistry
• 出版年：2005
• 出版时间：March 2005
• 年：2005
• 卷：16
• 期：2
• 页码：312 - 321
• 全文大小：408K
• 年卷期：v.16,no.2(March 2005)
• ISSN：1520-4812

文摘

Electrochemical DNA-based sensors that exploit the inherent sensitivity of DNA-mediated chargetransport (CT) to base pair stacking perturbations are capable of detecting base pair mismatches andsome common base damage products. Here, using DNA-modified gold electrodes, monitoring theelectrocatalytic reduction of DNA-bound methylene blue, we examine a wide range of base analoguesand DNA damage products. Among those detected are base damage products O4-methyl-thymine,O6-methyl-guanine, 8-oxo-guanine, and 5-hydroxy-cytosine, as well as a therapeutic base, nebularine.The efficiency of DNA-mediated CT is found not to depend on the thermodynamic stability of thehelix. However, general trends in how base modifications affect CT efficiency are apparent.Modifications to the hydrogen bonding interface in Watson-Crick base pairs yields a substantial lossin CT efficiency, as does added steric bulk. Base structure modifications that may induce baseconformational changes also appear to attenuate CT in DNA as do those that bury hydrophilic groupswithin the DNA helix. Addition and subtraction of methyl groups that do not disrupt hydrogen bondinginteractions do not have a large effect on CT efficiency. This sensitive detection methodology basedupon DNA-mediated CT may have utility in diagnostic applications and implicates DNA-mediatedCT as a possible damage detection mechanism for DNA repair enzymes.