Abstract：
Molecular engineering enables the creation of aptamers with novel functions, but the prerequisite is a deep understanding of their structure and recognition mechanism. The cellular-mesenchymal epithelial transition factor (c-MET) is garnering significant attention due to the critical role of the c-MET/HGF signaling pathway in tumor development and invasion. This study reports a strategy for constructing novel chimeric aptamers that bind to both c-MET and other specific proteins. c-MET was identified to be the molecular target of a DNA aptamer, HF3-58, selected through cell-SELEX. The binding structure and mechanism of HF3-58 with c-MET were systematically studied, revealing the scaffold, recognition, and redundancy regions. Through molecular engineering design, the redundancy region was replaced with other aptamers possessing stem-loop structures, yielding novel chimeric aptamers with bispecificity for binding to c-MET and specific proteins. A chimeric bispecific aptamer HF-3b showed the ability to mediate the adhesion of T-cells to tumor cells, suggesting the prospective utility in tumor immunotherapy. These findings suggest that aptamer HF3-58 can serve as a molecular engineering platform for the development of diverse multifunctional ligands targeting c-MET. Moreover, comprehensive understanding of the binding mechanisms of aptamers will provide guidance for the design of functional aptamers, significantly expanding their potential applications.
摘要：
分子工程能够创造具有新功能的适体，但前提是对其结构和识别机制的深刻理解。由于c-MET/HGF信号通路在肿瘤发展和侵袭中的关键作用，细胞间充质上皮转化因子（c-MET）引起了广泛关注。这项研究报道了构建与c-MET和其他特定蛋白质结合的新型嵌合适体的策略。c-MET被鉴定为DNA适体的分子靶标，HF3-58,通过细胞-SELEX选择。系统研究了HF3-58与c-MET的结合结构和机理,露出脚手架，认可,和冗余区域。通过分子工程设计,冗余区域被其他具有茎环结构的适体取代，产生新的嵌合适体，具有双特异性结合c-MET和特异性蛋白。嵌合双特异性适体HF-3b显示出介导T细胞与肿瘤细胞粘附的能力，提示在肿瘤免疫治疗中的前瞻性用途。这些发现表明适体HF3-58可以作为分子工程平台用于开发靶向c-MET的多种多功能配体。此外，全面了解适体的结合机制将为功能性适体的设计提供指导，显著扩大其潜在的应用。
