DNA cross-linking by diepoxybutane

二环氧丁烷 DNA 交联

• 批准号: 6727607
• 负责人: NATALIA Y TRETYAKOVA
• 金额: $ 23.82万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6727607
• 关键词: DNA damage; DNA repair; adduct; alkylation; animal tissue; carcinogens; chemical models; crosslink; cytotoxicity; deoxyribopolynucleotide; electrospray ionization mass spectrometry; environment related neoplasm /cancer; ethers; gel electrophoresis; high performance liquid chromatography; method development; nucleic acid purification; nucleic acid structure; nucleobase; phosphoester ligase; pollutant interaction; ultraviolet spectrometry

DESCRIPTION (provided by applicant): 1,2,3,4-Diepoxybutane (DEB) is an important metabolite of 1,3-butadiene, a major industrial chemical and environmental pollutant found in automobile exhaust and cigarette smoke. DEB is a bifunctional alkylating agent classified as "reasonably anticipated to be a human carcinogen" (U.S. Department of Health and Human Services). DEB is by far the most genotoxic metabolite of 1,3-BD, with mutagenic potency two orders of magnitude higher than that of butadiene monoepoxide. The cytotoxicity and genotoxicity of DEB is thought to be a result of its bifunctional nature. DEB can form DNA-DNA cross-links by simultaneously alkylating two nucleobases within the DNA duplex. Depending on their structure, the cross-linked lesions can induce cytotoxic or promutagenic effects. Although N7-G-N7-G DEB cross-links were first isolated from DNA over 40 years ago, no detailed structural information for these lesions is available. Gel electrophoresis studies have provided evidence for DEB cross-linking at adenine nucleobases, but did not allow structural identification of these lesions. The overall goal of the proposed research is to evaluate the role of DNA-DNA cross-linking in the genotoxic effects of diepoxybutane and 1,3-butadiene. We will investigate DEB-induced DNA cross-linking by a combination of mass spectrometry, molecular biology, and molecular modeling. First, we will structurally characterize DEB-DNA cross-links and determine sequence preferences for their formation. Next, we will evaluate the hydrolytic stability of DEB-DNA cross-links and their recognition by the E. coli UvrABC repair complex. Finally, the formation of DEB-DNA cross-links in rodent tissues following DEB exposure will be quantified by capillary HPLC-ESI-MS/MS methods. The results of this research will provide valuable information on the molecular mechanisms underlying the genotoxic activity of diepoxybutane. These findings will be extended to other bifunctional electrophiles to explain the observed differences in their biological activity.

描述（由申请人提供）：1,2,3,4-二环氧丁烷（DEB）是1,3-丁二烯的重要代谢物，1,3-丁二烯是汽车尾气和香烟烟雾中发现的主要工业化学品和环境污染物。 DEB 是一种双功能烷化剂，被归类为“合理预期为人类致癌物”（美国卫生与公众服务部）。 DEB 是迄今为止遗传毒性最强的 1,3-BD 代谢物，其致突变性比单环氧化物丁二烯高两个数量级。 DEB 的细胞毒性和基因毒性被认为是其双功能性质的结果。 DEB 可以通过同时烷基化 DNA 双链体中的两个核碱基来形成 DNA-DNA 交联。根据其结构，交联损伤可以诱导细胞毒性或促突变作用。尽管 N7-G-N7-G DEB 交联在 40 多年前首次从 DNA 中分离出来，但目前还没有这些损伤的详细结构信息。凝胶电泳研究为腺嘌呤核碱基处的 DEB 交联提供了证据，但无法对这些病变进行结构鉴定。本研究的总体目标是评估 DNA-DNA 交联在二环氧丁烷和 1,3-丁二烯的基因毒性作用中的作用。我们将结合质谱、分子生物学和分子建模研究 DEB 诱导的 DNA 交联。首先，我们将从结构上表征 DEB-DNA 交联并确定其形成的序列偏好。接下来，我们将评估 DEB-DNA 交联的水解稳定性及其被大肠杆菌 UvrABC 修复复合物的识别。最后，DEB 暴露后啮齿动物组织中 DEB-DNA 交联的形成将通过毛细管 HPLC-ESI-MS/MS 方法进行定量。这项研究的结果将为二环氧丁烷基因毒性活性的分子机制提供有价值的信息。这些发现将扩展到其他双功能亲电子试剂，以解释观察到的其生物活性差异。