核酸适体-抗体亲和作用机理研究及其在生物传感新方法中的应用

Aptamer is a novel artificially selected affinity ligand with advantages of high stability, low cost and simplicity of chemical modification, which is a promising substitution of antibody and other biological mimic receptors. Aptamer has a great potential in developing biochemical sensors and analytical methods. In this work, various analytical techniques including nuclear magnetic resonance, capillary electrophoresis, mass spectrometry will be applied to investigate the effect of DNA structural changes on affinity reaction between antibody and aptamer, for the purpose of further understanding the mechanism of the affinity interaction. Moreover, taking the advantage of the high specificity and high affinity combining with various DNA detection and amplification techniques when we figure out the basic interaction mechanism, we will propose more universal and more promising enzyme-linked aptamer assays (ELAA). A novel aptamer-antibody-antigen model with a sandwich structure will be constructed for highly sensitive detection of a variety of antigens, especially small molecule drugs. This work will open a new chapter of biochemical sensing researches integrating two aspects of nucleic acid technology and immunological technology and provide new detecting methods for the hot research areas of disease diagnosis, drug discovery and environment monitoring.

核酸适体是通过人工筛选的稳定性强、成本低、易化学修饰的新型亲和作用配体，可以有效地取代抗体及其他生物模拟受体，在发展生物传感器和其他分析方法中有广泛的应用前景。本研究拟利用抗体-核酸适体亲和体系，采用多种分析技术如核磁共振、毛细管电泳、质谱等研究核酸适体中核酸变异对于亲和作用的影响，理解核酸适体与目标抗体的相互作用机理。进一步，在充分理解作用机制的基础上，利用“人工抗体”核酸适体对目标抗体的高特异性及高亲和性，结合以核酸为基础的多种检测与信号放大模式，构建具有普适性更强以及应用潜力更大的酶联核酸适体分析传感新方法。我们将建立基于核酸适体/抗体/抗原的新型三明治夹心复合体系，实现多种抗原特别是小分子药物的高灵敏分析方法。本研究将开创综合核酸技术与免疫技术的生物传感领域的新篇章，为疾病诊断、药物开发、环境监测等热点研究领域提供新的检测手段。

核酸适体是通过人工筛选的稳定性强、成本低、易化学修饰的新型亲和作用配体，可以有效地取代抗体及其他生物模拟受体，在发展生物传感器和其他分析方法中有广泛的应用前景。本课题详细探究了抗鼠源IgG的核酸适体与鼠源IgG之间的相互作用，发现不同来源的鼠源IgG与该核酸适体结合力不同，通过毛细管电泳证实这种亲和差异性与Fc端的糖型不同有关，从而发现了能够与核酸适体特异性结合的麦芽五糖。通过多种方式筛选鼠源IgG的核酸适体，并用于ELAA传感器的构建中。借助DNAzyme作为识别和报告分子的双重功效构建了特异性强，应用范围广的DNAzyme传感器，并借助冰打印技术设计微胶囊阵列芯片实现了对多种目标物的POCT检测。在生物样品的前处理方面，设计并合成了官能团化的共价有机骨架材料，实现了对生物样品的选择性高效富集。本课题研究为疾病诊断、药物开发、环境监测等热点研究领域提供新的检测手段。