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Title: Base sequence effects on interactions of aromatic mutagens with DNA (deoxyribonucleic acid)

Technical Report ·
DOI:https://doi.org/10.2172/5643342· OSTI ID:5643342

The base-sequence dependence of the adduct conformations-derived from the covalent binding of trans-7,8-diol-anti-9,10--epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene (BPDE) (+) and (-) enantiomers to synthetic DNAs of defined base composition and sequence is described. The diol epoxide BPDE is the ultimate mutagenic and tumorigenic metabolite of benzo(a)pyrene, a common air pollutant, which is a byproduct of fossil fuel combustion processes. The covalent addition products of BPDE can be classified according to two types: (1) site I, involving carcinogen-DNA base stacking interactions, and (2) site II, in which the BPDE residue appears to be located at a partially external DNA binding site. The presence of site II adducts, rather than site I adducts, is correlated with high mutagenicities and tumorigenicities of polycyclic aromatic diol epoxides. It is shown here that the formation of site II adducts derived from the binding of the more tumorigenic (+)- BPDE enantiomer to DNA is particularly favored in deoxyguanine-rich sequences. 12 refs., 6 figs., 3 tabs.

Research Organization:
New York Univ., NY (USA). Dept. of Chemistry
Sponsoring Organization:
DOE/ER
DOE Contract Number:
FG02-88ER60674
OSTI ID:
5643342
Report Number(s):
DOE/ER/60674-2; ON: DE90002037
Country of Publication:
United States
Language:
English