蛋白质的核酸适配体筛选的研究进展

摘要

Aptamers are selected through systematic evolution of ligands by exponential enrich-ment( SELEX),and are artificially synthesized single-stranded DNA or RNA with high affinity and specificity against a wide variety of target molecules. Since some functional proteins play the key role in life process,aptamers against proteins have attracted great attention in the last decade,and are used in basic research and wide applications. The performance of aptamers depends on their affinity,specificity and stability. In recent years,many SELEX methods have been developed to enhance the properties of aptamers,improve selection efficiency and reduce cost. The main procedure of SELEX includes the isolation of target-aptamer compound,optimi-zation the random ssDNA library,enrichment of ssDNA and the analysis and characterization of selected aptamers. In this review,we summarize the developments of aptamer selection meth-ods for protein targets since 2005,discuss their shortcomings and limitations,and introduce the optimization of ssDNA library,aptamer sequence character and analytical methods for their affinity analysis.%核酸适配体是通过指数富集系统配体进化（ SELEX）筛选获得的，与靶标具有高亲和力和特异性结合的单链DNA或 RNA。蛋白质是生命进程中的关键功能分子。近年来，以蛋白质为靶标的适配体筛选在蛋白质相关的基础及应用研究领域受到广泛关注。核酸适配体应用性能的优劣取决于其亲和力、特异性与稳定性。目前，适配体筛选方法的优化主要是提高筛选效率、提升适配体性能及降低筛选成本。适配体主要筛选步骤包括复合物分离、核酸库优化、次级库的富集、适配体序列分析以及亲和力表征等。迄今为止，以蛋白质-核酸复合物的分离为核心步骤的适配体筛选方法有20余种。本文归纳总结了2005年以来以蛋白质为靶标的适配体筛选技术，讨论了各方法的缺陷与局限。介绍了核酸库的设计优化方法、适配体的序列特征，以及常用的亲和力表征方法。