School of Physical Science and Technology, ShanghaiTech University , Shanghai 201210, China.
Department of Chemistry, National Central University , Taoyuan 32001, Taiwan.
J Am Chem Soc. 2017 May 17;139(19):6530-6533. doi: 10.1021/jacs.7b01794. Epub 2017 May 8.
We show that an enzyme maintains its biological function under a wider range of conditions after being embedded in metal-organic framework (MOF) microcrystals via a de novo approach. This enhanced stability arises from confinement of the enzyme molecules in the mesoporous cavities in the MOFs, which reduces the structural mobility of enzyme molecules. We embedded catalase (CAT) into zeolitic imidazolate frameworks (ZIF-90 and ZIF-8), and then exposed both embedded CAT and free CAT to a denature reagent (i.e., urea) and high temperatures (i.e., 80 °C). The embedded CAT maintains its biological function in the decomposition of hydrogen peroxide even when exposed to 6 M urea and 80 °C, with apparent rate constants k (s) of 1.30 × 10 and 1.05 × 10, respectively, while free CAT shows undetectable activity. A fluorescence spectroscopy study shows that the structural conformation of the embedded CAT changes less under these denaturing conditions than free CAT.
我们通过从头合成的方法将酶嵌入金属有机骨架（MOF）微晶体中，发现其在更宽的条件范围内保持了生物功能。这种增强的稳定性源于酶分子在 MOF 的介孔腔中的受限，这降低了酶分子的结构流动性。我们将过氧化氢酶（CAT）嵌入沸石咪唑酯骨架（ZIF-90 和 ZIF-8）中，然后将嵌入的 CAT 和游离的 CAT 暴露于变性试剂（即尿素）和高温（即 80°C）下。嵌入的 CAT 在分解过氧化氢时保持其生物功能，即使在暴露于 6 M 尿素和 80°C 的情况下，其表观速率常数 k（s）分别为 1.30×10 和 1.05×10，而游离的 CAT 则几乎没有活性。荧光光谱研究表明，在这些变性条件下，嵌入的 CAT 的结构构象变化小于游离的 CAT。
