Development of a Quantitative Liquid Chromatography/Electrospray Mass Spectrometric Assay for a Mutagenic Tobacco Specific Nitrosamine-Derived DNA Adduct, O6-[4-Oxo-4-(3-pyridyl)butyl]-2‘-deoxyguanosine
| Autor: | Natalia Y. Tretyakova, Renée S. Mijal, Anthony E. Pegg, Nancy L. Fleischer, Lisa A. Peterson, Rebecca Ziegel, Nicole M. Thomson |
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| Rok vydání: | 2004 |
| Předmět: |
Detection limit
Spectrometry Mass Electrospray Ionization Electrospray Guanine Nitrosamines Chromatography Pyridines Selected reaction monitoring Deoxyguanosine General Medicine Isotope dilution Toxicology Tandem mass spectrometry Adduct DNA Adducts Mice chemistry.chemical_compound chemistry Nitrosamine Tobacco DNA adduct Animals Female Chromatography Liquid Mutagens |
| Zdroj: | Chemical Research in Toxicology. 17:1600-1606 |
| ISSN: | 1520-5010 0893-228X |
| Popis: | Liquid chromatography with electrospray tandem mass spectrometry (LC/ESI-MS/MS) was employed to quantify O6-[4-oxo-4-(3-pyridyl)butyl]-2'-deoxyguanosine (O6-pobdG), a mutagenic adduct formed by pyridyloxobutylating nitrosamines. Selected reaction monitoring (SRM) of the neutral loss of the sugar from protonated molecules of the adduct, [M + H - 116]+, was utilized for detection of O6-pobdG in pyridyloxobutylated DNA from both in vitro and in vivo sources. Quantitation was based on isotope dilution with synthetic O6-[1,2,2-2H3-4-oxo-4-(3-pyridyl)butyl]-2'-deoxyguanosine. The detection limits in this study were less than 5 fmol of pure standard and 50 fmol in 1.5 mg of DNA. This method was validated by comparing adduct levels measured with the LC/ESI-MS/MS method to those obtained with radiochemical methods in DNA alkylated with the model pyridyloxobutylating agent, [5-3H]4-(acetoxymethylnitrosamino)-1-(3-pyridyl)-1-butanone ([5-3H]NNKOAc). The pyridyloxobutyl 2'-deoxyguanosine adduct coeluting with the deuterated standard disappeared when NNKOAc-treated DNA had been reacted with the repair protein, O6-alkylguanine-DNA alkyltransferase. This result confirms that the coeluting peak is solely O6-pobdG. Preliminary studies with liver DNA isolated from NNKOAc-treated mice demonstrated that this method can be used to quantify O6-pobG in DNA from in vivo sources. The improved sensitivity and specificity of adduct detection afforded by this LC/ESI-MS/MS method will allow us to explore the role of O6-pobdG in the toxicological properties of pyridyloxobutylating nitrosamines. |
| Databáze: | OpenAIRE |
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