基于光引发可控聚合诱导多重蛋白质组装体的仿生构筑

This project aims at the scientific problem of how to realize the precisely controllable and ordered assembly of biomacromolecules in micro scale, and its simulation on dynamic behavior transformation and multistage elaborate structure of cell. By taking advantage of the in situ photoinitiated RAFT polymerization strategy, combined with the targeting modified protein and bioorthogonal reaction, on the one hand, we want to establish a method to induce homogeneous or heterogeneous protein assembly with building blocks of clear structure by in situ photoinitiated RAFT polymerization from the view of structure design, and mainly focuses on exploring the influence of the biomacromolecules conformation changes on the assembly morphology; on the other hand, with polymerization as the driving force, to realize the dynamic behavior change such as fission and fusion of the microcapsule, especially study on the mechanism and influential factors; furthermore, by control on the different direction of the initiated graft polymerization, to achieve orientated polymerization on the homogeneous or heterogeneous microcapsule, which would simulate the multistage elaborate structure of cell, such as cytoskeleton, cell wall and core-shell structure. The successful implementation of this project will not only lay the foundation for the protein microcapsules to simulate relatively complex and advanced behavior of artificial cells, so as to fill the gap in this field especially for internal cell structure simulation and construction; it will also provide new ideas for the preparation of complex biomimetic materials with well-defined structure、regulated morphology and adjusted function.

本项目拟针对如何实现生物大分子微尺度组装体的精准可控有序构筑及其对细胞动态行为转变、多级精细结构的模拟这一科学问题，拟利用原位光引发RAFT聚合诱导的方法，结合蛋白质靶向修饰和生物正交反应，一方面从结构设计角度出发利用结构明确的构筑基元建立一种原位光引发RAFT聚合诱导单一或杂合蛋白质组装体的方法，并着重探究生物大分子基元构象变化对于组装体形貌的影响机制；同时以聚合为驱动力，实现微胶囊的分裂、融合等动态行为的转变并研究其形成机制和影响因素；进而通过设计控制不同的引发接枝聚合方向，构筑单一或杂合微胶囊结构上的定向聚合，实现其对细胞复杂精细结构如细胞骨架、细胞外墙及核壳结构的仿生模拟构筑。本项目的成功执行不但将为实现蛋白质微胶囊朝向人工细胞的相对复杂、高级行为模拟奠定基础，从而填补该领域特别是对于细胞内部结构模拟构筑的空白；也将为制备结构明确、形貌可调控、功能可调节的复杂仿生材料提供新的思路。

因其操作的便捷性及良好的调控能力，光响应成为研究人工细胞动态行为过程中一种广为关注的手段。针对如何实现生物大分子微尺度组装体的可控有序构筑及其对细胞动态行为转变、多级精细结构的模拟这一科学问题，利用原位光引发RAFT聚合诱导的方法，在细胞体外和体内分别成功实现了具有较窄多分散性的非天然大分子的合成，并展现出其在调控生物体的功能和行为方面重要的潜在应用，如可进行光合产氢和抗凝集。同时构建出具有光响应动态调控能力的蛋白质组装体，实现其对酶促反应速率的灵活调控及可逆动态调控。凝聚体是在外部刺激下易产生复杂动态行为的开放型分子密集系统，对于研究生物大分子微尺度组装体构筑的人工细胞动态行为转变是非常理想的模型；通过在蛋白质胶囊内部包载凝聚体微滴形成杂合人工多级微区室（如细胞骨架、细胞外墙及核壳结构等）仿生构筑，模拟了细胞内无膜子细胞器，同时模拟了巨噬细胞吞噬细菌的行为，其可调控对细菌的选择性捕获和吞噬。基于生物分子相分离的策略，在人工微区室中构筑多相共存微滴，通过不同的外部环境刺激实现了对多室微滴结构可逆空间重构以及相关生物反应进程的程序性调控。.在基金资助下，共发表项目号（51873050）标注的SCI论文15篇，授权国家发明专利2项，培养及协助培养研究生11人。