| 摘要: | 酵素具有促進生化反應及專一性等特性，應用範圍廣。但對於環境耐受度低，需要通過固定化提高其穩定性，並實現回收再利用以降低成本。而有機金屬框架材料(Metal-organic Frameworks, MOFs)具備多孔隙以及高穩定性等特質，很適合作為酵素載體。因此本實驗室於2015年開發了類沸石咪唑骨架材料-90 (Zeolitic Imidazolate Framework-90, ZIF-90)封裝過氧化氫酶(Catalase, CAT)的原位創新合成法（de novo approach）。此方法雖為酵素固定化提出了一個新的思維，但耗時長且僅適用在特定的MOFs中。故在2019年，我們改以溶液輔助研磨法（Liquid‐Assisted Grinding），將酵素封裝在UiO-66-NH2等MOFs中。而此方法尚有需要被優化的地方，例如需要使用到有機溶劑、合成時間長達五分鐘、封裝酵素須分為兩步驟而非一鍋法完成以及無法以單晶包覆酵素等，若能改進上述合成的缺陷勢必能使溶液輔助研磨法具備更強的競爭力。
本篇論文成功的透過溶液輔助研磨法在10秒內合成單晶包覆的酵素材料複合物，CAT@ZIF-90，相較於本實驗室之前的研究，酵素活性從2.68 × 10−2提高至1.98 × 10−1。而為了更進一步了解酵素材料複合物的合成機制，利用不同溶液進行溶液輔助研磨，並成功推論出供後續以溶液輔助研磨法合成其他種類MOFs時緩衝溶液選擇的依據。並以上述成果進行酵素材料複合物包覆率提升的研究，得到最高包覆率約為34%，制定出一個新的能有效提高包覆率的策略。;Enzymes have characteristics such as promoting biochemical reactions and specificity, making them widely applicable. However, their low tolerance to environmental conditions necessitates immobilization to enhance stability and enable recycling to reduce costs. Metal-organic frameworks (MOFs), with their porous nature and high stability, are well-suited as enzyme carriers. Therefore, in 2015, our laboratory developed a de novo approach for encapsulating catalase (CAT) in zeolitic imidazolate framework-90 (ZIF-90). While this method provided a new perspective on enzyme immobilization, it was time-consuming and only applicable to specific MOFs. Consequently, in 2019, we adopted the liquid-assisted grinding (LAG) to encapsulate enzymes in MOFs such as UiO-66-NH2. However, this method still required optimization, such as the use of organic solvents, a synthesis time of up to five minutes, a two-step encapsulation process instead of a one-pot method, and the inability to encapsulate enzymes in single crystals. Improving these synthesis drawbacks would undoubtedly enhance the competitiveness of the LAG method.
This paper successfully synthesized single-crystal encapsulated enzyme-MOF biocomposites, CAT@ZIF-90, in 10 seconds using the LAG. Compared to our previous research, the enzyme activity increased from 2.68 × 10−2 to 1.98 × 10−1. To further understand the synthesis mechanism of enzyme-MOF biocomposites, different solutions were used for LAG, successfully deducing the criteria for selecting buffer solutions for synthesizing other types of MOFs using the LAG. Based on these results, a study to improve the loading of enzyme-MOF biocomposites was conducted, achieving a maximum loading of approximately 34%, and formulating a new strategy that effectively enhances the loading. |
