OPTICAL PROPERTIES OF NUCLEIC ACID CONSTITUENTS

核酸成分的光学性质

• 批准号: 3295109
• 负责人: LEIGH B CLARK
• 金额: $ 7.59万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 1990-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3295109
• 关键词: DNA binding protein; adenine; benzimidazoles; chromophore; circular dichroism; conformation; dichroism; dipole moment; electronic spectra; hydrogen bond; molecular stacking; nucleic acid structure; nucleobase; phosphates; polarimetry; polynucleotides; purines; pyrimidines; ribose; solutions; spectrometry; thymine; ultraviolet spectrometry

The proposed work is aimed at developing and refining methods used to obtain nucleic acid conformations in solution from optical measurements. Such information and the corresponding models it produces are prerequisite for understanding the dynamics and biological mechanisms of nucleic acids. The most powerful and widely used optical methods for sensing detailed solution state conformations are circular dichroism and linear dichroism spectroscopies, however both require specific optical information regarding the electric dipole transition moments of the purine and pyrimidine monomeric chromophores. Much of these essential data have never been available, and this lack of monomer data has undermined the interpretation of the optical properties of polynucleotides. The overall aim of the proposed research is to provide all necessary missing information. It is therefore proposed to obtain absorption curves extending well into the vacuum UV region for radiation polarized along various axes of purine and pyrimidine single crystals. The absorption curves will be obtained from experimental polarized reflection spectra through Kramers- Kronig analysis. Exciton coupling will be treated with an iterative procedure in an effort to account for crystal intermolecular interaction effects and to extract free molecule properties for the crystal spectra. The adenine and thymine chromophores are the least well studied, so that crystals containing these systems will form the bulk of the initial effort. In addition to determining the principal polarization direction of each transition we hope whenever possible to obtain the other components of the absorptivity tensor. Sequences of crystals involving base, nucleoside, nucleotide and ionic forms (if available) will be studied in order to answer long-standing questions about the effect of ribose and phosphate substitution and protonation on the base chromophore. Hydrogen bonded A:T and G:C complexes will be examined to verify and study the striking conclusions drawn from the only previous study of such complexes. We plan to grow and examine dinucleoside phosphate single crystals in order to study the effects of stacking interactions and to refine the protocols for calculating the optical properties of the polynucleotide in general. Longer oligonucleotide systems will also be sought for study.

拟议的工作旨在发展和完善方法 用于从光学光谱中获得溶液中的核酸构象 测量. 这些信息和相应的模型， 生产是理解动力学的先决条件， 核酸的生物学机制 最有力量也 广泛使用的用于检测详细溶液状态的光学方法 构象是圆二色性和线性二色性 然而，光谱学都需要特定光学信息 关于嘌呤的电偶极跃迁矩， 嘧啶单体发色团。 这些基本的 数据从来没有可用，这种缺乏单体数据， 破坏了对光学性质的解释， 多核苷酸。 拟议研究的总体目标是 提供所有必要的缺失信息。因此提议 以获得延伸到真空UV中的吸收曲线 沿嘌呤的各个轴沿着极化的辐射区域， 嘧啶单晶 将获得吸收曲线 从实验偏振反射光谱通过克莱默斯- Kronig分析。 激子耦合将用一个 为了解释晶体，迭代过程 分子间相互作用和提取游离分子 晶体光谱的性质。 腺嘌呤和胸腺嘧啶 发色团是研究得最少的，所以晶体 包含这些系统将构成初期工作的主要部分。 除了确定的主要偏振方向， 每一个过渡，我们希望尽可能获得其他 吸收率张量的分量。 晶体序列 包括碱基、核苷、核苷酸和离子形式（如果 可用）将进行研究，以回答长期存在的问题 关于核糖和磷酸取代的影响的问题 和质子化作用。 氢键A：T 和G：C复合物将被检查，以验证和研究 从以前唯一的研究中得出的惊人结论， 配合物 我们计划培养并检测磷酸二核苷 为了研究堆积效应， 相互作用，并完善用于计算光学 多核苷酸的特性。 长 还将寻求寡核苷酸系统用于研究。