构象调控的组合核酸适体多靶标筛选新方法研究

项目名称： 构象调控的组合核酸适体多靶标筛选新方法研究

项目编号： No.21205124

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 分析化学

项目作者： 邴涛

作者单位： 中国科学院化学研究所

项目金额： 25万元

中文摘要： 核酸适体是从随机核酸文库中筛选得到的可与靶标特异性结合的单链寡核苷酸，在分离、分析以及生物医学领域有着广泛的应用前景。虽然核酸适体研究已取得较大进展，但其筛选仍然是该领域的瓶颈。筛选过程中往往要将靶分子固定，固定后靶分子的结构和性质会发生变化，导致得到的核酸适体与游离靶分子的亲和力与特异性降低。核酸适体探针的构建往往引入构象调控单元，也会导致其亲和力与特异性降低，影响实际应用。针对筛选和应用中的问题，本项目拟以我们筛选的链霉亲和素核酸适体为构象调控元件，建立构象调控的组合核酸适体筛选新方法，以实现免固定、多靶标同时筛选；所得到的组合核酸适体无需进一步设计，可直接用于靶标的分离与检测；去掉其构象调控部分即可获得常规的核酸适体。研究工作包括新型DNA文库的设计、筛选过程的优化、核酸适体的表征及其分析应用；同时对核酸适体筛选的进化规律，及其与靶分子相互作用的构效关系等基本问题展开基础研究。

中文关键词： 核酸适配体；筛选；生物标志物；构象调控；肿瘤

英文摘要： Aptamers that are selected in vitro from random DNA or RNA libraries by SELEX (Systematic Evolution of Ligands by EXponential enrichment) technique have been extensively explored recently because of their potential applications in the areas such as analysis and biomedicine. Although research of aptamers has made great progress during the past decades, the aptamer selection is still the main bottleneck of this area. In order to separate bound sequences from unbound sequences during the selection procedure, targets are usually immobilized on solid support. The immobilization always changes the structure and properties of targets and results in the lower affinity and specificity of the obtained aptamers. The sensitivity and specificity of aptamer probes are often compromised because of the introduction of an allosteric element. In this proposal, we aim to develop a novel selection method for allosteric aptamers by combining a streptavidin binding aptamer as an allosteric element. By this method, allosteric combined aptamers against non-fixed multi-targets can be generated simultaneously. The obtained allosteric aptamers can be used directly in detection and separation of targets without post-optimization or construction. The conventional aptamers can easily be obtained through removing the streptavidin binding apta

英文关键词： Aptamer；SELEX；Biomarker；Allosteric regulation；Cancer