北京理工大学王博团队报道了利用自修复和结晶过程实现共价有机框架中有效的酶包封。相关研究成果发表在2023年6月7日出版的国际知名学术期刊《美国化学会杂志》。

脆性酶在结晶多孔材料中的固定化为扩大生物催化剂的应用提供了新的机会。然而，由于多孔宿主的孔径和/或苛刻的合成条件的限制，酶在固定化过程中经常受到尺寸限制或变性。

利用共价有机框架（COFs）的动态共价化学特征，该文报道了一种在自修复和结晶过程中将酶包裹在COFs中的预保护策略。酶首先被装载在初始生长阶段形成的具有中孔的低结晶聚合物网络中，这可以为酶提供有效的保护，使其免受恶劣的反应条件的影响，随后在无序聚合物的自修复和结晶过程中进行包封，形成晶状框架。

令人印象深刻的是，酶的生物活性在包封后可以很好地保持，并且获得的enzyme@COFs也显示出优异的稳定性。此外，预保护策略避开了酶的大小限制，其多功能性通过具有不同大小和表面电荷的酶以及双酶级联系统得到了验证。

该项研究提供了一种将酶包裹在坚固的多孔载体中的通用设计思想，并有望开发出高性能的固定化生物催化剂。

附：英文原文

Title: Harnessing Self-Repairing and Crystallization Processes for Effective Enzyme Encapsulation in Covalent Organic Frameworks

Author: Yufeng Zhang, Chunyan Xing, Zhenjie Mu, Ziru Niu, Xiao Feng, Yuanyuan Zhang, Bo Wang

Issue&Volume: June 7, 2023

Abstract: Immobilization of fragile enzymes in crystalline porous materials offers new opportunities to expand the applications of biocatalysts. However, limited by the pore size and/or harsh synthesis conditions of the porous hosts, enzymes often suffer from dimension limitation or denaturation during the immobilization process. Taking advantage of the dynamic covalent chemistry feature of covalent organic frameworks (COFs), herein, we report a preprotection strategy to encapsulate enzymes in COFs during the self-repairing and crystallization process. Enzymes were first loaded in the low-crystalline polymer networks with mesopores formed at the initial growth stage, which could offer effective protection for enzymes from the harsh reaction conditions, and subsequently the encapsulation proceeded during the self-repairing and crystallization of the disordered polymer into the crystalline framework. Impressively, the biological activity of the enzymes can be well-maintained after encapsulation, and the obtained enzyme@COFs also show superior stability. Furthermore, the preprotection strategy circumvents the size limitation for enzymes, and its versatility was verified by enzymes with different sizes and surface charges, as well as a two-enzyme cascade system. This study offers a universal design idea to encapsulate enzymes in robust porous supports and holds promise for developing high-performance immobilized biocatalysts.

DOI: 10.1021/jacs.3c04183

Source: https://pubs.acs.org/doi/10.1021/jacs.3c04183