MUTAGENIC CONSEQUENCES OF BENZO[A]PYRENE ADDUCTS

了解多环芳烃的作用机理 碳氢化合物，如苯并(A)芘(BP)，能够诱导 突变，必须回答三个问题。(1)什么加成物 诱导哪些突变？(2)这些加合物是如何诱导这些突变的 突变(即直接突变或作为中间体)？(3)为什么会这样 加合物会导致它们所做的突变吗？中描述的工作 这项建议主要集中在回答第一个问题。 对于N_2-鸟嘌呤，N(7)-鸟嘌呤和N_6-腺嘌呤加合物 来自多环芳香烃。主要的加合物形成了 从体内的BP(即BP-N_2-GUA)构建成双标准， 大肠杆菌，使用化学合成和组合的病毒载体 重组DNA技术。继维修改造之后 精通并修复缺陷的大肠杆菌细胞，没有突变体 在BP-N-GUA损伤的水平上被发现 1%。构建了一个新的载体，并构建了BP-n2-gua 将其单链转化到大肠杆菌细胞中。这个 寻找BP-N2-GUA衍生突变体的工作正在进行中。通过类似的方式 方法将BP-N_2-GUA构建成穿梭载体。 转染人细胞，以研究诱变剂 这种损伤在人类细胞中的后果。腺嘌呤加合物 似乎在致癌基因的诱变激活中起着重要作用。 7-溴甲基1-12-N6-腺嘌呤加合物 甲苯并[a]并三烯(BrMBA)将内置于相关病毒中 载体及其在大肠杆菌细胞中的诱变后果研究。 BPDE的N(7)-GUA加合物是化学不稳定的， 可能排除了它们整合到载体中的可能性 重组DNA和化学合成技术。一个 研究核辐射致突变后果的另一种方法 提出了不稳定加合物的概念。

To understand the machanism by which polycyclic aromatic hydrocarbons, such as benzo(a)pyrene (BP), are able to induce mutations, three questions must be answered. (1) What adducts induce what mutations? (2) How do these adducts induce these mutations (i.e., directly or as intermediates)? (3) Why do these adducts induce the mutations that they do? The work described in this proposal is primarily focused on answering the first question for N2-Guanine, N(7)-Guanine and N6-Adenine adducts derived from polycyclic aromatic hydrocarbons. The major adduct formed from BP in vivo (i.e., BP-N2-Gua) was built into a double standed, E. coli, viral vector using a combination of chemical synthetic and recombinant DNA techiques. Following transformation of repair proficient and repair deficient E. coli cells, no mutants were found to have arisen from the BP-N2-Gua lesion at the level of 1%. A new vector was constructed and BP-N2-Gua was built into it, made single stranded and transformed into E. coli cells. The search for BP-N2-Gua derived mutants is in progress. By similar methods BP-N2-Gua will be built into a shuttle vector, and transfected into human cells in order to study the mutagenic consequences of this lesion in human cells. Adenine adducts appear to be important in the mutagenic activation of oncogenes. The N6-Adenine adduct of 7-bromomethy1-12- methylbenz(a)antracene (BrMBA) will be built into a related viral vector and its mutagenic consequences studied in E. coli cells. N(7)-Gua adducts of BPDE are chemically unstable, which probably precludes their incorporation into vectors utilizing recombinant DNA and chemical synthetic techniques. An alternative method for studying the mutagenic consequences of unstable adducts is proposed.