食品危害物核酸适配体-靶标结合机制研究

Aptamers have attracted much attention in recent years because of their high affinity, strong specificity, easy modification, large amount of chemical synthesis, and no need for animal experiments. But how is the adaptation between the aptamer and the target molecule during the SELEX process? What are the dynamics, mechanisms of action and recognition mechanism of the aptamer-target interaction? How to effectively improve the rigidity of the aptamer structure and solve the stability of the structure of the aptamer? Can the theoretical design of aptamers on the basis of an in-depth analysis of the relationship between the aptamer-target structure-activity? There is still a lack of research on the related fields, which seriously restricts the development of aptamers. Therefore, based on the large number of screening aptamers in our previous work, using food hazards aptamers as model, the project intends to optimize the structure of oligonucleotide aptamer by sequence tailoring, base substitution and modification, conformation analysis by sequence. And combine with NMR and CD chromatography, atomic force microscopy, fluorescence polarization, isothermal titration calorimetry, microscale thermophoresis and molecular simulation and docking technology to investigate different types of aptamer-target molecular basis for the process of recognition in-depth, to reveal the molecular mechanism of the interaction between aptamer and target molecule, then establish correspinding theoretical model,aiming to provide theoretical guidance for optimal design, ligand molecular probe screening, structure/activity relationship and evaluation of performance of aptamers.

核酸适配体因具有亲和力高、特异性强、易于修饰、可大量化学合成、不需要动物实验等特点成为近年来生物识别分子领域的研究热点。然而筛选过程中适配体与靶标分子之间是如何适应的？适配体-靶标相互作用的有关动力学、作用机制和识别机理如何？如何有效提高适配体结构刚性、解决适配体结构稳定性问题？能否在深入分析适配体-靶标构效关系的基础上理论性设计适配体？相关研究仍然缺乏，严重制约了核酸适配体的发展。因此，在前期大量筛选的基础上，本项目拟以食品危害物核酸适配体为模型，采用序列剪裁、碱基替换及修饰、构象分析等对核酸适配体结构序列进行优化，结合核磁共振、圆二色谱、原子力显微镜、荧光偏振、等温滴定量热法、微量热泳动以及分子模拟和对接等技术手段深入研究不同类型“适配体-靶标”识别过程的分子基础，揭示适配体与靶标分子相互作用的分子机制，建立相应理论模型，为适配体分子探针的设计、筛选、构/效关系和性能评价提供理论指导。

核酸适配体因具有亲和力高、特异性强、易于修饰、可大量化学合成、不需要动物实验等特点成为近年来生物识别分子领域的研究热点。然而筛选过程中适配体与靶标分子之间是如何适应的？适配体-靶标相互作用的有关动力学、作用机制和识别机理如何？如何有效提高适配体结构刚性、解决适配体结构稳定性问题？能否在深入分析适配体-靶标构效关系的基础上理论性设计适配体？相关研究仍然缺乏，严重制约了核酸适配体的发展。因此，在前期大量筛选获得的食品危害物适配体基础上，以食品危害物核酸适配体为模型，采用序列剪裁、碱基替换及修饰、构象分析等对核酸适配体结构序列进行了系统的分析优化，同时结合核磁共振、圆二色谱、原子力显微镜、荧光偏振、等温滴定量热法、微量热泳动以及分子模拟和对接等技术手段深入研究不同类型结构适配体的结合功效，阐明了“适配体-靶标”结合的构效关系，为深入洞察“适配体-靶标”识别过程的提供了分子基础，另外，揭示了适配体与靶标分子相互作用的分子机制，建立相应理论模型，为适配体分子探针的高效设计、筛选、构/效关系和性能评价提供理论指导。最后，基于"适配体-靶标"结合机制融合多功能纳米荧光材料构建了多种食品危害物分析传感平台。拓展了适配体在实际应用中的应用场景