Wiaderkiewicz R, Walter Z, Reimschussel W
Acta Biochim Pol. 1986;33(2):73-85.
Methylation in vitro of DNA by three methyl-14C-labelled organophosphorus insecticides has been studied. The ability of methylbromphenvinphos, methylparathion and malathion to methylate N-7 of guanine in DNA can be expressed as 100:40:15. Among the methylation products, no O6-methylguanine, a known mutagen, was found. Both in the reaction with dsDNA and with ssDNA 7-methyl-guanine was the main methylation product. However, all methyl derivatives of adenine (3-methyladenine, 1-methyladenine and 7-methyladenine) constituted about 40% and 50% of all methylation products in the case of dsDNA and ssDNA, respectively. The only methyl derivative of pyrimidine we have identified was 3-methylcytosine. In the case of dsDNA 3-methylcytosine appeared in small amounts but in the alkylated ssDNA 3-methylcytosine C constituted about 20% of all alkylation products.
研究了三种甲基 - 14C标记的有机磷杀虫剂在体外对DNA的甲基化作用。甲基溴苯磷、甲基对硫磷和马拉硫磷使DNA中鸟嘌呤的N - 7甲基化的能力可表示为100:40:15。在甲基化产物中，未发现已知的诱变剂O6 - 甲基鸟嘌呤。在与双链DNA和单链DNA的反应中，7 - 甲基鸟嘌呤都是主要的甲基化产物。然而，腺嘌呤的所有甲基衍生物（3 - 甲基腺嘌呤、1 - 甲基腺嘌呤和7 - 甲基腺嘌呤）在双链DNA和单链DNA的情况下分别占所有甲基化产物的约40%和50%。我们鉴定出的嘧啶唯一甲基衍生物是3 - 甲基胞嘧啶。在双链DNA的情况下，3 - 甲基胞嘧啶含量很少，但在烷基化的单链DNA中，3 - 甲基胞嘧啶C约占所有烷基化产物的20%。
