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%的人类肿瘤株和病毒转化株是 由于明显缺乏烷基化试剂而引起的过敏性 烷基鸟嘌呤烷基转移酶。这种酶可以消除烷基化作用。 在鸟嘌呤的0-6位有损伤，而在其他位置无损伤 DNAD.Yarosh博士与我们单位合作，已经能够 从人肝脏中部分提纯酶并提高 这种蛋白质的多克隆抗体。研究已经开始 以研制出针对该蛋白的单抗。使用高 亲和抗体，我们将能够进一步纯化这一点 蛋白。在充分纯化的情况下，部分氨基酸序列 可以获得并用于合成寡核苷酸探针，该探针 将用于筛选人肝cDNA文库。这样的抗体 也可用于筛选人肝组织表达文库。

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.