Fluorescent Nucleosides and Oligonucleotides

描述(申请人提供)：该计划的目标是设计、合成和实施新的荧光核苷类似物，作为核酸结构、动力学和识别的探针。指导这项工作的主要标准是保持与天然碱基结构尽可能高的相似性，将发射转移到更长的波长，并保持足够的发射量子效率。本项目的具体目标是：(1)设计“理想的”荧光核苷类似物，它将具有以下特征：(1)与天然碱基的结构高度相似，以忠实地模拟它们的大小和形状，以及杂交和识别特性；(2)红移的吸收光谱，以最大限度地减少与天然碱基的吸收重叠；(3)良好的发射量子效率和长的发射波长(最好在可见光范围内)；(2)设计简明的合成方法，以获得所需的核碱基类似物；(3)研究新核苷的光物理特性；(4)合成和表征修饰的DNA和RNA寡核苷酸；(5)对修饰的寡核苷酸进行生物物理和光物理表征；(6)在生物物理和发现实验中实现有前景的发光类似物。人们日益认识到核酸修饰及其对疾病的影响，以及耐药病原体的迅速出现，因此有必要开发新的工具来有效地研究核酸，包括它们的识别特性和外源因子的改变。发射核苷类似物将被用于新的基于荧光的分析。这些检测将有助于：(1)检测在致癌过程中发挥重要作用的DNA损伤(例如8-oxoG)；(2)在荧光A位类似物的辅助下发现针对细菌核糖体的新抗生素；(3)在荧光DIS构建物的辅助下发现新型抗艾滋病毒药物；以及(4)通过发射探针检测蛋白质毒素，例如蓖麻毒素，检测其脱纯的RNA产物。这些研究将促进对与疾病发展有关的关键生物学过程的基本了解，并将通过促进药物发现对改善人类健康产生长期影响。公共卫生相关性：核酸(DNA和RNA)在生物学中发挥核心作用，因此对疾病的发展和人类健康产生巨大影响。发展有效的基于荧光的工具来探索DNA和RNA的修饰或它们与潜在治疗剂的相互作用将促进新的诊断方法，并将促进药物发现。

DESCRIPTION (provided by applicant): The goal of the proposed program is to design, synthesize and implement new fluorescent nucleoside analogs as probes for nucleic acids structure, dynamics and recognition. The main criteria directing the proposed work are to maintain the highest possible structural similarity to the natural nucleobases, to shift the emission to longer wavelengths, and to retain adequate emission quantum efficiency. The specific aims of this project are: (1) To design "ideal" fluorescent nucleoside analog that will possess the following characteristics: (i) A high structural similarity to the native nucleobases to faithfully mimic their size and shape, as well as hybridization and recognition properties, (ii) A red shifted absorption spectrum to minimize overlap with the absorption of the natural bases, (iii) A respectable emission quantum efficiency and a long emission wavelength (preferably in the visible range); (2) To devise concise synthetic approaches to the desired nucleobase analogs; (3) To examine the photophysical characteristics of the new nucleosides; (4) To synthesize and characterize modified DNA and RNA oligonucleotides; (5) To biophysically and photophysically characterize the modified oligonucleotides; and (6) To implement the promising emissive analogs in biophysical and discovery assays. The increased appreciation for nucleic acids modifications and their impact on diseases, as well as the rapid emergence of resistant pathogens, necessitate the development of new tools for the effective study of nucleic acids, including their recognition properties and alteration by exogenous agents. The emissive nucleoside analogs will be implemented into novel fluorescence-based assays. These assays will facilitate: (i) the detection of DNA lesions (e.g., 8-oxoG), that play important roles in carcinogenesis, (ii) the discovery of new antibiotics targeting the bacterial ribosome, assisted by fluorescent A-site analogs, (iii) the discovery of novel anti-HIV agents, assisted by fluorescent DIS constructs, and (iv) the detection of protein toxins, such as ricin, via emissive probes that detect their depurinated RNA products. These investigations will advance the fundamental understanding of key biological processes related to disease development and will have long-term impact on improving human health by facilitating drug discovery. PUBLIC HEALTH RELEVANCE: Nucleic acids (DNA and RNA) play central roles in biology and, as such, have immense impact on the development of diseases and, as such, on human health. Advancing effective fluorescence-based tools for exploring the modification of DNA and RNA or their interactions with potential therapeutic agents will advance new diagnostic approaches and will facilitate drug discovery.