Enzyme immobilization within metal–organic frameworks (MOFs) is a promising solution to avoid denaturation and thereby utilize the desirable properties of enzymes outside of their native environments. The biomimetic mineralization strategy employs biomacromolecules as nucleation agents to promote the crystallization of MOFs in water at room temperature, thus overcoming pore size limitations presented by traditional postassembly encapsulation. Most biomimetic crystallization studies reported to date have employed zeolitic imidazole frameworks (ZIFs). Herein, we expand the library of MOFs suitable for biomimetic mineralization to include zinc(II) MOFs incorporating functionalized terephthalic acid linkers and study the catalytic performance of the enzyme@MOFs. Amine functionalization of terephthalic acids is shown to accelerate the formation of crystalline MOFs enabling new enzyme@MOFs to be synthesized. The structure and morphology of the enzyme@MOFs were characterized by PXRD, FTIR, and SEM-EDX, and the catalytic potential was evaluated. Increasing the linker length while retaining the amino moiety gave rise to a family of linkers; however, MOFs generated with the 2,2′-aminoterephthalic acid linker displayed the best catalytic performance. Our data also illustrate that the pH of the reaction mixture affects the crystal structure of the MOF and that this structural transformation impacts the catalytic performance of the enzyme@MOF.

中文翻译：

---

氨基官能团使得能够在室温下通过仿生结晶水合成基于羧酸的 MOF


将酶固定在金属有机框架（MOF）内是一种很有前景的解决方案，可以避免变性，从而在其天然环境之外利用酶的所需特性。仿生矿化策略采用生物大分子作为成核剂，促进MOF在室温下在水中结晶，从而克服了传统后组装封装带来的孔径限制。迄今为止报道的大多数仿生结晶研究都采用沸石咪唑骨架（ZIF）。在此，我们扩展了适合仿生矿化的 MOF 库，将锌（II）MOF 纳入功能化对苯二甲酸连接体中，并研究了酶@MOF 的催化性能。对苯二甲酸的胺官能化可加速结晶 MOF 的形成，从而能够合成新的酶@MOF。通过PXRD、FTIR和SEM-EDX对酶@MOFs的结构和形貌进行了表征，并评估了催化潜力。在保留氨基部分的同时增加接头长度产生了接头家族；然而，使用 2,2'-氨基对苯二甲酸连接体生成的 MOF 显示出最佳的催化性能。我们的数据还表明，反应混合物的pH值会影响MOF的晶体结构，并且这种结构转变会影响enzyme@MOF的催化性能。