Formation of deoxyguanosine cross-links from calf thymus DNA treated with acrolein and 4-hydroxy-2-nonenal.
Acrolein (AC) and 4-hydroxy-2-nonenal (HNE) are endogenous bis-electrophiles that arise from the oxidation of polyunsaturated fatty acids. AC is also found in high concentrations in cigarette smoke and automobile exhaust. These reactive α,β-unsaturated aldehyde (enal) covalently modify nucleic acids, to form exocyclic adducts, where the three-carbon hydroxypropano unit bridges the N1 and N(2) positions of deoxyguanosine (dG). The bifunctional nature of these enals allows them to undergo reaction with a second nucleophilic group and form DNA cross-links. These cross-linked enal adducts are likely to contribute to the genotoxic effects of both AC and HNE. We have developed a sensitive mass spectrometric method to detect cross-linked adducts of these enals in calf thymus DNA (CT DNA) treated with AC or HNE. The AC and HNE cross-linked adducts were measured by the stable isotope dilution method, employing a linear quadrupole ion trap mass spectrometer and consecutive reaction monitoring at the MS(3) or MS(4) scan stage. The lower limit of quantification of the cross-linked adducts is ∼1 adduct per 10(8) DNA bases, when 50 μg of DNA is assayed. The cross-linked adducts occur at levels that are ∼1-2% of the levels of the monomeric 1,N(2)-dG adducts in CT DNA treated with either enal.
Kozekov
Ivan D
ID
Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235-1822, USA.
Turesky
Robert J
RJ
Alas
Guillermo R
GR
Harris
Constance M
CM
Harris
Thomas M
TM
Rizzo
Carmelo J
CJ
D000171:Acrolein / Q000737:chemistry* / Q000633:toxicity; D000447:Aldehydes / Q000737:chemistry* / Q000633:toxicity; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000737:chemistry*; D018736:DNA Adducts / Q000737:chemistry / Q000302:isolation & purification; D003849:Deoxyguanosine / Q000737:chemistry*; D052616:Solid Phase Extraction; D021241:Spectrometry, Mass, Electrospray Ionization; D013997:Time Factors
D000447:Aldehydes; D018736:DNA Adducts; D000171:Acrolein; D004247:DNA; C427203:calf thymus DNA; D003849:Deoxyguanosine; C027576:4-hydroxy-2-nonenal