SPECIFICITY OF DNA REPAIR FOR OXIDIZED ABASIC SITES

描述：自由基对DNA的损伤，这与 癌的发生、正常的衰老过程和神经退行性变， 各种病变。 这些损伤中的许多是各种无碱基损伤（位点 基础损失）。 这些包括1 -氧化、4 -氧化或片段化 脱氧核糖残基，试剂如H2 O2的已知产物，电离 放疗和博莱霉素 这种损伤具有细胞毒性和致突变性 可能是上述年龄和疾病影响的基础，但 这些氧化脱氧核糖损伤很难测量 具体地，灵敏地和定量地通过现有的方法。 这 该项目建议为这种分析开发新方法，重点是 利用DNA修复酶释放特定损伤进行分析 通过先进的质谱分析和毛细管电泳技术。 这些方法将用于探索个体的形成和修复 体内氧化脱碱基位点。 非碱性（AP）核酸内切酶已经被广泛应用于 参与这些损伤的修复，但这种特异性还没有被发现。 在活体中证明。 关键的研究包括分析染色体 DNA，以确定E.大肠杆菌外切核酸酶III H_2O_2诱导的DNA损伤，以及E.大肠杆菌核酸内切酶IV和酵母Apnl在 氧化脱碱基位点的修复。 人类猿核酸内切酶的能力 以纠正E.杆菌和酵母 将通过新的方法进行评估，突变形式的核酸内切酶也是如此。 IV和Apnl。 这项工作不仅对未来的工作很重要， 了解自由基损伤在衰老、癌症和 神经变性，但它也将提供量子改善， 一类重要的氧化DNA的分子分析方法 损害

DESCRIPTION: Free radical damage to DNA, which has been associated with carcinogenesis, the normal aging process, and neurodegeneration, produces a variety of lesions. Many of these damages are various abasic lesions (sites of base loss). These include 1 -oxidized, 4 -oxidized or fragmented deoxyribose residues, known products of agents such as H2O2, ionizing radiation and bleomycin. Such damages have cytotoxic and mutagenic potential that might underlie the age and disease effects cited above, but these oxidized deoxyribose lesions have been difficult to measure specifically, sensitively and quantitatively by existing methods. This project proposes to develop new methods for such analysis, with an emphasis on the use of DNA repair enzymes to liberate specific damages for analysis by advanced techniques of mass spectrometry and capillary electrophoresis. These methods will be used to explore the formation and repair of individual oxidized abasic sites in vivo. Abasic (AP) endonucleases have been implicated in the repair of these damages, but this specificity has not been demonstrated in vivo. Key proposed studies include analyzing chromosomal DNA to determine the specific role of E. coli exonuclease III in repairing H2O2-induced DNA damage, and of E. coli endonuclease IV and yeast Apnl in the repair of oxidized abasic sites. The ability of human Ape endonuclease to correct specific repair defects in mutant strains of E. coli and yeast will be assessed by the novel methods, as will mutated forms of endonuclease IV and Apnl. Not only will this work be important for future work toward understanding the role of free-radical damage in aging, cancer, and neurodegeneration, but it will also provide quantum improvements in the methodology for molecular analysis of an important class of oxidative DNA damage.