抗体药物偶联物（ADCs）实现了细胞毒药物的肿瘤靶向输送，ADCs定点偶联技术通过设计精确的分子结构而具有更好的可控性、稳定性和代谢性质，成为该领域的前沿热点。糖链定点ADCs（gsADCs）将药物连接在抗体N297糖基化位点，无需对抗体的氨基酸序列进行工程改造，在定点ADCs技术中具有独特的优势。我们前期建立和发展了糖苷内切酶催化的抗体糖链定点偶联技术，为新型gsADCs的设计和成药性研究提供了新颖的策略、奠定了坚实的基础。同时，多步骤的抗体改造工艺、糖链底物结构的局限、gsADCs分子的多样性不足成为该方法亟待解决的瓶颈问题。本项目通过寡糖底物筛选实现单酶“一步法”抗体偶联，克服双酶“三步法”的复杂工艺；扩展底物范围，涵盖全长和缩短型糖链结构；设计多样化连接子结构、连接方式、亲水性片段等，对gsADCs成药性进行系统性研究；最终为推动基于糖链定点ADCs策略的新药研发提供原创思路。

Antibody drug conjugates (ADCs) selectively delivers cytotoxic payloads to the tumors. Through the design of precise molecular structures, site-specific ADCs has been dramatically developed owing to its better controllability, stability and pharmacodynamics. Meanwhile, glycosite-specific ADCs, which conjugated the drugs onto the glycosylation site N297 of an antibody and without the needs of antibody amino acid engineering, possesses distinct advantages among site-specific ADCs. Previously, we have established and developed the glyco-site specific conjugation strategy via ENGases catalyzed antibody glycoengineering, providing a novel strategy and sound basics in the studies of gsADCs drug design and druggability evaluation. However, multiple steps in antibody glycoengieering, the limitation of glycan substrates and the lack of gsADCs diversites have dramatically restricted the development of this strategy, which are urgently needed to be solved. Hence, by screening novel glycan structures, our project aims to establish single-enzyme catalyzed “one-step” antibody conjugation strategy, overcoming the complex processes of dual-enzyme “three-step” conjugation. Meanwhile, by covering full-length and trimmed glycan structures, we will expand the substrates scope that are applied in gsADCs. In addition, by designing various linker structures, linking strategies, hydrophilic moieties, we will systematically study the druggability of diverse gsADCs. Finally, we anticipate to supply an original mentality in promoting the new drug research and development of site-specific ADCs that are based on glycosylation site.