DNA DAMAGE STUDIED BY ULTRAFAST SPECTROSCOPY

通过超快光谱研究 DNA 损伤

• 批准号: 3181783
• 负责人: THOMAS M NORDLUND
• 金额: $ 7.88万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-06-01 至 1990-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3181783
• 关键词: DNA; conformation; fluorescence polarization; fluorescence spectrometry; nucleic acid structure; nucleobase; nucleotides; pyrimidine dimers; pyrimidines; radiation genetics; radiobiology; temperature; ultraviolet spectrometry

Excited electronic states of nucleic acids and other biological molecules are the precursors of virtually all forms of radiation damage to the genetic material. These precursor states are poorly understood at present because they are extremely short-lived at physiological temperatures, with lifetimes on the order of 10-13 to 10-11 s. The research proposed will use state-of-the-art ultrafast methods to directly study the nucleic acid states excited by ultraviolet light which lead to damage sties on the nucleotide helix. The goals are to determine how the excitation/damage process depends upon base content and conformation of the helix, how helix intercalating agents can intercept energy deposited on the helix and dissipate the energy without nucleotide damage, and why most of the damage sites seems to involve pyrimidine dimers and adducts. The primary methods to be used are time- and wavelength-resolved absorption and fluorescence spectroscopy using well-defined synthetic nucleotide oligomers and polymers designed to answer specific questions concerning damage mechanisms. These studies will for the first time directly probe the time evolution of the major energetic events caused by ultraviolet light absorption and will quantitate rates and routes of energy disposition in DNA which leads to base damage.

核酸和其他生物分子的激发电子态 是几乎所有形式的辐射损害的前兆， 遗传物质 目前人们对这些前兆状态知之甚少 因为它们在生理温度下寿命极短， 寿命大约为10-13到10-11秒。 该研究将使用 最先进的超快方法直接研究核酸 紫外光激发态，导致损伤sties上的 核苷酸螺旋 目标是确定激励/损伤 这一过程取决于螺旋的碱基含量和构象， 嵌入剂可以拦截沉积在螺旋上的能量， 在没有核苷酸损伤的情况下耗散能量，以及为什么大多数损伤 位点似乎涉及嘧啶二聚体和加合物。 主要方法 要使用的是时间和波长分辨的吸收和荧光 使用定义明确的合成核苷酸低聚物和聚合物的光谱学 旨在回答有关损伤机制的具体问题。 这些 研究将首次直接探讨时间的演变， 紫外线吸收引起的重大能量事件， DNA中的能量处置的定量速率和途径， 基地损坏。