MASS SPECTROMETRY FOR DNA ADDUCTS STRUCTURES

DNA 加合物结构的质谱分析

• 批准号: 6344722
• 负责人: MICHAEL L GROSS
• 金额: $ 16.87万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2001-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6344722
• 关键词: DNA damage; adduct; animal genetic material tag; carbopolycyclic compound; chemical carcinogenesis; electrospray ionization mass spectrometry; estrogens; gas chromatography mass spectrometry; matrix assisted laser desorption ionization; nucleic acid structure; technology /technique development

Recently we have established that high-energy tandem mass spectrometry is sufficiently specific for determining structure of DNA adducts. When coupled with fast atom bombardment mass spectrometry, however, the detection limits and sensitivity are not adequate to support investigations of adducts in the femtomole range. To overcome this limitation, we propose to develop and compare three mass spectrometric approaches for high- sensitivity detection and structure determination of DNA adducts. Tandem foursector mass spectrometry with extended array detection has recently been coupled with electrospray ionization in our laboratory. Continued development is the highest priority because the product-ion spectra have sufficient specificity to distinguish isomeric adducts. Efforts will be extended to understand the basic ions chemistry that underpins these collisionally activated dissociation spectra. In parallel, we will use routine triple quadrupole mass spectrometry coupled via electrospray ionization with HLPLC. The low-energy collisionally induced fragmentations that are endemic to the triple quadrupole will be evaluated and compared with those occurring under the high-energy conditions of the four-sector instrument. The third approach is matrix-assisted laser desorption ionization (MALDI), which will be developed as a screening approach and as a structure-verification method by means of both molecular-ion and post- source=decomposition monitoring. In addition. MALDI capabilities will be extended to studies in which sites of modification and depurination in oligonucleotides must be located. The overall goal is to establish the merits of various mass spectrometric approaches to structure determination of DNA adducts, to understand the underlying ion chemistry, and to apply appropriately the methods to samples isolated from in vitro and in vivo studies.

最近，我们确定高能串联质谱是 足以确定DNA加合物的结构。 什么时候 结合快速原子轰击质谱法， 检测极限和灵敏度不足以支持调查 femtomole范围内的加合物。 为了克服这一限制，我们建议 开发和比较三种高质谱法 DNA加合物的灵敏度检测和结构测定。 串联 最近具有扩展阵列检测的四部门质谱法 与我们的实验室中的电喷雾电离相结合。 持续 开发是优先事项，因为产品离子光谱具有 足够的特异性以区分异构内基。 努力将是 扩展以了解为这些基础的基本离子化学反应 碰撞激活的解离光谱。 同时，我们将使用 常规三倍四极杆质谱法，通过电喷雾耦合 用HLPLC电离。 低能碰撞引起的碎片 将评估和比较三倍的三倍的特有 那些发生在四个扇区的高能条件下 乐器。 第三种方法是矩阵辅助激光解吸 电离（MALDI），将作为筛选方法开发 通过分子离子和后的结构验证方法 来源=分解监视。 此外。 Maldi的能力将是 扩展到研究的研究 必须找到寡核苷酸。 总体目标是确定 各种质谱法的优点 DNA加合物的理解，以了解潜在的离子化学物质并应用 适当地从体外和体内分离的样品的方法 研究。