REACTIVE INTERMEDIATES IN PHOTOCEMICAL REACTIONS OF BIOLOGICALLY RELEVANT PURINES

生物学相关嘌呤光化学反应中的反应中间体

• 批准号: 3936825
• 负责人: RAFAEL ARCE
• 金额: --
• 依托单位: UNIVERSITY OF PUERTO RICO RIO PIEDRAS
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3936825
• 关键词: adenine nucleotides; crosslink; dimer; electron spin resonance spectroscopy; flash photolysis; guanine nucleotides; nuclear magnetic resonance spectroscopy; nucleic acids; photochemistry; polynucleotides; purine nucleosides; purine nucleotides; pyrimidine nucleosides; pyrimidine nucleotides; radiation carcinogenesis; ultraviolet radiation

Ultraviolet radiation produces different types of lesions on DNA which unrepaired could lead to lethal, mutagenic and tumorigenic effects. In the last decade there have been reports on the formation of purine photoproducts in UV irradiated DNA which could lead to deleterious effects. Photochemical studies on monomeric purines and their derivatives from our laboratory indicate photodestruction yields as high as the one observed for monomeric pyrimidines. Also, the formation of highly reactive intermediates have been observed. These could initiate reaction with other bases and/or molecules close to the DNA. Our main objectives are: 1. To study and characterize the excited states and reactive intermediates participating in the photodestruction and photochemical reactions of purine deoxynucleotide dimers, oligo and polynucleotides. These will be characterized from their absorption spectra and kinetic behavior obtained with laser and conventional flash photolysis and fluorescence spectrometry. These studies will provide information on the mechanism of formation of the recently observed purine photoproducts in DNA. 2. Identify the stable products in the photodestruction of deoxyguanosine and deoxyguanosine monophosphate and establish its photodestruction mechanism. 3. Identify the intermediates participating in purine photoinitiated cross linking reactions with organic compounds considered to be models for the side chain of amino acids. The information to be obtained will aid in the understanding of the detrimental effects of UV light on living systems such as mutations, aging and carcinogenesis.

紫外线辐射在DNA上产生不同类型的病变 未经修复的可能导致致命，诱变和肿瘤性 效果。 在过去的十年中，有关于 在紫外线辐照的DNA中形成嘌呤光药物，可以 导致有害影响。 单体光化学研究 来自我们实验室的嘌呤及其衍生物表明 光电降低的产量与单体观察到的光子屈服高 嘧啶。 此外，形成高反应性中间体 已经观察到。 这些可能引发其他基础的反应 和/或分子接近DNA。 我们的主要目标是： 1。研究和表征激发态和反应性 参与光电片段和的中间体 嘌呤脱氧核苷酸二聚体，寡核和光化学反应 多核苷酸。 这些将从它们的吸收中表征 用激光和常规的光谱和动力学行为 闪光光解和荧光光谱法。 这些研究会 提供有关最近形成机理的信息 观察到DNA中的嘌呤光产物。 2。确定稳定产品 脱氧鸟苷和脱氧鸟苷单磷酸盐并建立 光检查机制。 3。确定参加嘌呤的中间体 光启动的交叉链接与有机化合物的反应 被认为是氨基酸侧链的模型。 要获得的信息将有助于理解 紫外线对生活系统的有害影响，例如 突变，衰老和癌变。