Kojima M, Degawa M, Hashimoto Y, Tada M
Laboratory of Biochemistry, Aichi Cancer Center Research Institute, Nagoya, Japan.
Biochem Biophys Res Commun. 1991 Sep 16;179(2):817-23. doi: 10.1016/0006-291x(91)91890-o.
M13mp10 phage DNA modified with the carcinogen 3-methoxy-4-aminoazobenzene (3-MeO-AAB) or the noncarcinogen 2-methoxy-4-aminoazobenzene (2-MeO-AAB) was used as a template for E.coli DNA polymerase I. Analysis of the reaction products on DNA sequencing gels showed that with both types of compound the induced lesions blocked DNA synthesis, mainly at one base prior to guanine adducts, but that the inhibition by 3-MeO-AAB-adducts was substantially greater than that by 2-MeO-AAB-adducts. Thus different effects on DNA replication between 3-MeO-AAB- and 2-MeO-AAB-adducts might be a reflection of differences in their carcinogenic potency.
用致癌物3-甲氧基-4-氨基偶氮苯（3-MeO-AAB）或非致癌物2-甲氧基-4-氨基偶氮苯（2-MeO-AAB）修饰的M13mp10噬菌体DNA被用作大肠杆菌DNA聚合酶I的模板。对DNA测序凝胶上反应产物的分析表明，对于这两种化合物，诱导的损伤都阻断了DNA合成，主要是在鸟嘌呤加合物之前的一个碱基处，但3-MeO-AAB加合物的抑制作用明显大于2-MeO-AAB加合物。因此，3-MeO-AAB和2-MeO-AAB加合物对DNA复制的不同影响可能反映了它们致癌潜力的差异。
