In situ encapsulation of cellulase in conventional metal–organic frameworks (MOFs) is restrained by harsh preparation conditions and the rather small pores of the frameworks. Herein, We developed a mesoporous Zn-based MOF (Zn-mIm) prepared under mild conditions is well-suited for in situ encapsulation of cellulase. In brief, cellulase is encapsulated through coprecipitation of cellulase and Zn-mIm precursors, identified as cellulase@Zn-mIm. This approach enhances the binding between cellulase and Zn-mIm. The cellulase loading also significantly increases, and the highest loading is up to 350 mg g⁻¹. Moreover, cellulase@Zn-mIm shows superior tolerance to basic environments and retains 65% of its activity at pH 8, whereas that of free cellulase drops to only 10%. Cellulase@Zn-mIm also exhibits good recyclability and retains 77% of its activity after four cycles. Furthermore, the introduction of cellulase leads to structural defects during Zn-mIm preparation, resulting in the formation of large pores, which facilitate mass transfer and thus enhance enzymatic efficiency.

Graphic Abstract

中文翻译：

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新型中孔金属-有机骨架中纤维素酶的原位包封

常规金属-有机框架（MOF）中纤维素酶的原位封装受到苛刻的制备条件和框架很小的孔的限制。本文中，我们开发了在温和条件下制备的介孔锌基MOF（Zn-mIm），非常适合纤维素酶的原位封装。简而言之，纤维素酶是通过纤维素酶和Zn-mIm前体的共沉淀来封装的，被识别为cellulase @ Zn-mIm。这种方法增强了纤维素酶和Zn-mIm之间的结合。纤维素酶的负荷也显着增加，最高负荷可达350 mg g ^-1。而且，纤维素酶@ Zn-mIm对碱性环境表现出优异的耐受性，并在pH 8时保持其活性的65％，而游离纤维素酶的活性仅下降至10％。纤维素酶@ Zn-mIm还表现出良好的可回收性，并且在四个循环后仍保留其77％的活性。此外，纤维素酶的引入导致Zn-mIm制备期间的结构缺陷，导致形成大孔，这促进了质量传递并因此提高了酶促效率。

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