TY - JOUR
T1 - Structure elucidation of a 6-methylbenzo[a]pyrene-DNA adduct formed by horseradish peroxidase in vitro and mouse skin in vivo
AU - Rogan, Eleanor G.
AU - Hakam, Alaeddin
AU - Cavalieri, Ercole L.
PY - 1983/10/15
Y1 - 1983/10/15
N2 - Activation of polycyclic aromatic hydrocarbons (PAH) by horseradish peroxidase (HRP) with H2O2 has been studied as a model system for one-electron oxidation. This peroxidase has been used to catalyze binding of 6-[14C]methylbenzo[a]pyrene (BP-6-CH3) to DNA, which was purified, hydrolyzed to deoxyribonucleosides and analyzed by high pressure liquid chromatography (HPLC). The predominant hydrocarbon-DNA adduct observed was identified as BP-6-CH3 bound at the 6-methyl group to the 2-amino group of dG, confirming that activation by HRP occurs by one-electron oxidation. When DNA from mouse skin treated in vivo with [14C]BP-6-CH3 was purified, hydrolyzed and analyzed by HPLC, a profile was observed which was qualitatively similar to that from the peroxidase system. In particular, the identified adduct with the hydrocarbon bound at the 6-methyl group to the 2-amino group of dG was obtained. These results demonstrate that one-electron oxidation is the mechanism of activation by HRP for aromatic hydrocarbons and indicate that the same mechanism may occur in mouse skin, a target tissue for hydrocarbon carcinogenesis.
AB - Activation of polycyclic aromatic hydrocarbons (PAH) by horseradish peroxidase (HRP) with H2O2 has been studied as a model system for one-electron oxidation. This peroxidase has been used to catalyze binding of 6-[14C]methylbenzo[a]pyrene (BP-6-CH3) to DNA, which was purified, hydrolyzed to deoxyribonucleosides and analyzed by high pressure liquid chromatography (HPLC). The predominant hydrocarbon-DNA adduct observed was identified as BP-6-CH3 bound at the 6-methyl group to the 2-amino group of dG, confirming that activation by HRP occurs by one-electron oxidation. When DNA from mouse skin treated in vivo with [14C]BP-6-CH3 was purified, hydrolyzed and analyzed by HPLC, a profile was observed which was qualitatively similar to that from the peroxidase system. In particular, the identified adduct with the hydrocarbon bound at the 6-methyl group to the 2-amino group of dG was obtained. These results demonstrate that one-electron oxidation is the mechanism of activation by HRP for aromatic hydrocarbons and indicate that the same mechanism may occur in mouse skin, a target tissue for hydrocarbon carcinogenesis.
KW - Carcinogenic activation
KW - DNA adduct structure
KW - Horseradish peroxidase
KW - Mouse skin
KW - One-electron oxidation
KW - Polycyclic aromatic hydrocarbons
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U2 - 10.1016/0009-2797(83)90151-5
DO - 10.1016/0009-2797(83)90151-5
M3 - Article
C2 - 6640783
AN - SCOPUS:0021014376
VL - 47
SP - 111
EP - 122
JO - Chemico-Biological Interactions
JF - Chemico-Biological Interactions
SN - 0009-2797
IS - 1
ER -