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

R.S.Day、III、D.Yarosh和其他人已经表明，大约20%的 人肿瘤细胞株和病毒转化株对 由于明显缺乏烷基鸟嘌呤而导致的烷基化试剂 烷基转移酶。这种酶去除了0-6位的烷基化损伤。 但不在DNA中的其他位置。D.Yarosh博士在合作中 我们的单位已经能够部分提纯人类肝脏中的酶 并产生针对这种蛋白质的多克隆抗体。研究表明， 开始开发这种蛋白质的克隆抗体。使用高 有了亲和抗体，我们才能进一步纯化这一蛋白质。使用 可以得到足够的纯化、部分氨基酸序列和 用于合成将用于筛选的寡核苷酸探针 人肝cDNA文库。这种抗体也可用于筛查 人肝cdna表达文库。

R. S. Day, III, D. Yarosh, and others have shown that approximately 20% of human tumor lines and viral transformed lines are hypersensitive to alkylating agents due to an apparent absence of alkylguanine alkyltransferase. This enzyme removes alkylation damage at the 0-6 position of guanine but not at other sites in DNA. Dr. D. Yarosh in collaboration with our unit has been able to partially purify the enzyme from human liver and raise polyclonal antibodies to this protein. Studies have been initiated to develop monoclonal antibodies to this protein. With high affinity antibodies, we will be able to further purify this protein. With sufficient purification, partial amino acid sequence can be obtained and used to synthesize oligonucleotide probes which will be used to screen human liver cDNA libraries. Such antibodies can also be used to screen human liver cDNA expression libraries.