Quantitative analysis of 4-aminobiphenyl-C8-deoxyguanosyl DNA adducts produced in vitro and in vivo using HPLC-ES-MS.
Electrospray mass spectrometry (ES-MS) is a powerful tool for analysis of carcinogen-adducted DNA. In this study, we developed a quantitative isotope dilution method for analysis of N-(deoxyguanosine-8-yl)-4-aminobiphenyl (dG-C8-4-ABP), the principal nucleoside adduct derived from enzymatic hydrolysis of 4-aminobiphenyl (4-ABP)-modified DNA. The method used column switching valves to perform on-line sample concentration and cleanup, which permitted direct analysis of enzymatic DNA hydrolysates using narrow-bore liquid chromatography (LC). ES-MS detection was performed using a single quadrupole instrument by monitoring M+H+ and two fragment ions characteristic for dG-C8-4-ABP, along with M+H+ and a fragment ion for the deuterated internal standard. The detection limit for dG-C8-4-ABP in DNA hydrolysates was approximately 10 pg on-column, equivalent to 0.7 dG-C8-4-ABP adducts in 10(7) normal nucleotides for a sample containing 100 microg DNA. The method was applied to the analysis of calf thymus DNA modified in vitro through reaction with N-hydroxy-4-ABP and of hepatic DNA isolated from mice treated in vivo with two dose levels of 4-ABP.
Doerge
D R
DR
National Center for Toxicological Research, Jefferson, AR 72079, USA and Instituto Superior Tecnico, P-1049-001 Lisboa, Portugal.
Churchwell
M I
MI
Marques
M M
MM
Beland
F A
FA
D000611:Aminobiphenyl Compounds / Q000737:chemistry* / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004247:DNA / Q000187:drug effects; D018736:DNA Adducts / Q000032:analysis*; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D051379:Mice
D000611:Aminobiphenyl Compounds; D018736:DNA Adducts; C053420:N-(deoxyguanosin-8-yl)-4-aminobiphenyl; D004247:DNA; D003849:Deoxyguanosine