DNA DAMAGE BY ALKYLATING AGENTS AND THEIR REPAIR IN HUMAN TUMOR CELLS

R. S. Day，III和其他人已经表明，大约20%的人类 肿瘤细胞系和病毒转化细胞系对烷基化高度敏感 由于明显缺乏烷基鸟嘌呤烷基转移酶， 我们有 在这些烷基化反应中未检测到特异性mRNA的任何一致缺失。 敏感的mer细胞系。 我们已经能够部分净化 人体肝脏中的酶 这种酶可以去除 在DNA中鸟嘌呤的对位，而不是在其他位点。 我们计划进一步 对这种酶进行鉴定并将其纯化到氨基酸 可以获得序列信息。

R. S. Day, III and others have been shown that approximatley 20% of human tumor lines and viral transformed lines are hypersensitive to alkylating agents due to an apparent absence of Alkylguanine Alkytransferase. We have not detected any consistent absence of a specific mRNA in these alkylation sensitive, mer-cell lines. We have been able to partially purify the enzyme from human liver. This enzyme removes alkylationdamage at the 0pposition of guanine but not at other sites in DNA. We plan to further characterize this enzyme and purify it to the point where amino acid sequence information can be obtained.