Fluorescent Nucleosides and Oligonucleotides

描述（由申请人提供）：拟议计划的目标是设计，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。指导拟议工作的主要标准是保持与天然核碱基的最高可能的结构相似性，将发射转移到更长的波长，并保持足够的发射量子效率。本课题的具体目标是：（1）设计“理想的”荧光核苷类似物，使其具有以下特征：（i）与天然核碱基的高度结构相似性，以忠实地模拟它们的大小和形状，以及杂交和识别性质，（ii）红移吸收光谱，以最小化与天然碱基的吸收的重叠，（iii）可观的发射量子效率和长发射波长（2）设计所需核碱基类似物的简明合成方法;（3）检查新核苷的生物物理特性;（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药理学和生物化学表征;和（6）在生物物理和发现测定中实施有前景的发射类似物。对核酸修饰及其对疾病的影响的日益认识，以及耐药病原体的迅速出现，使得开发新的工具用于有效研究核酸，包括其识别特性和外源性试剂的改变成为必要。发射性核苷类似物将被应用于新的基于荧光的测定中。这些测定将有助于：（i）DNA损伤的检测（例如，8-oxoG），其在致癌作用中起重要作用，（ii）发现靶向细菌核糖体的新抗生素，通过荧光A位点类似物辅助，（iii）发现新的抗HIV剂，通过荧光DIS构建体辅助，和（iv）通过检测其脱嘌呤RNA产物的发射探针检测蛋白毒素，如蓖麻毒素。这些研究将推进对与疾病发展相关的关键生物学过程的基本理解，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）在生物学中起着核心作用，因此对疾病的发展和人类健康具有巨大影响。推进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，将推进新的诊断方法，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.