Abstract：
D-allulose, a low-calorie rare sugar catalyzed by D-allulose 3-epimerase (DAE), is highly sought after for its potential health benefits. However, poor reusability and stability of DAE limited its popularization in industrial applications. Although metal-organic frameworks (MOFs) offer a promising enzyme platform for enzyme immobilization, developing customized strategies for MOF immobilization of enzymes remains challenging. In this study, we introduce a designable strategy involving the construction of bimetal-organic frameworks (ZnCo-MOF) based on metal ions compatibility. The DAE@MOFs materials were prepared and characterized, and the immobilization of DAE and the enzymatic characteristics of the MOF-immobilized DAE were subsequently evaluated. Remarkably, DAE@ZnCo-MOF exhibited superior recyclability which could maintain 95 % relative activity after 8 consecutive cycles. The storage stability is significantly improved compared to the free form, with a relative activity of 116 % remaining after 30 days. Molecular docking was also employed to investigate the interaction between DAE and the components of MOFs synthesis. The results demonstrate that the DAE@ZnCo-MOF exhibited enhanced catalytic efficiency and increased stability. This study introduces a viable and adaptable MOF-based immobilization strategy for enzymes, which holds the potential to expand the implementation of enzyme biocatalysts in a multitude of disciplines.
摘要：
D-阿洛酮糖,D-阿洛酮糖3-差向异构酶（DAE）催化的低热量稀有糖，因其潜在的健康益处而备受追捧。然而,DAE的可重用性和稳定性差限制了其在工业应用中的推广。尽管金属有机框架（MOFs）为酶固定化提供了一个有前途的酶平台，开发MOF固定化酶的定制策略仍然具有挑战性。在这项研究中,我们介绍了一种可设计的策略，涉及基于金属离子相容性的双金属有机框架（ZnCo-MOF）的构建。制备并表征了DAE@MOFs材料，随后评估了DAE的固定化和MOF固定化DAE的酶学特性。值得注意的是,DAE@ZnCo-MOF表现出优异的可回收性，在连续8次循环后可保持95％的相对活性。与游离形式相比，储存稳定性显著提高，30天后剩余的相对活性为116%。分子对接还用于研究DAE与MOFs合成组分之间的相互作用。结果表明,DAE@ZnCo-MOF表现出提高的催化效率和提高的稳定性。这项研究介绍了一种可行且适应性强的基于MOF的酶固定化策略，它具有在众多学科中扩展酶生物催化剂实施的潜力。
