Tahsiri Z, Niakousari M, Hosseini S M H, Majdinasab M
Department of Food Science and Technology, Shiraz University, Shiraz, Iran.
Department of Food Science and Technology, Shiraz University, Shiraz, Iran.
Int J Biol Macromol. 2022 Jun 1;209(Pt A):1422-1429. doi: 10.1016/j.ijbiomac.2022.04.111. Epub 2022 Apr 21.
Magnetic nanoparticle coated with manganese‑aluminum layered double hydroxide (Fe3O4/Mg-Al-CO3-LDH) was prepared and used as porous support for ficin (EC 3.4.22.3) as a model enzyme. Structural characteristics were studied by XRD, FTIR, SEM and light scattering. The quantity of immobilized ficin on the mentioned LDH and non-magnetic LDH was measured and enzyme activity, stability and reusability were compared. Results revealed that the core and shell structure of FeO/Mg-Al-CO-LDH makes it better dispersion compared to the pristine Mg-Al-CO-LDH. Ficin showed strong affinity to absorption of the surface of mentioned LDHs nanosheet especially magnetic LDH, confirmed that the existence of FeO in the core structure of magnetic FeO/Mg-Al-CO-LDH caused better dispersion of LDH nanocrystal shell compared to pristine LDH moreover, enzyme which immobilized on the magnetic LDH supports, can be recovered by magnetic interaction. The storage stability of free ficin, immobilized ficin on the Mg-Al-CO-LDH and FeO/Mg-Al-CO-LDH during a period of 120 days lost about 75%, 30%, and 20% of their initial activities, respectively.
制备了包覆有锰铝层状双氢氧化物的磁性纳米颗粒（Fe3O4/Mg-Al-CO3-LDH），并将其用作无花果蛋白酶（EC 3.4.22.3）这一模型酶的多孔载体。通过X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）和光散射研究其结构特征。测定了固定在上述层状双氢氧化物（LDH）和非磁性LDH上的无花果蛋白酶的量，并比较了酶活性、稳定性和可重复使用性。结果表明，与原始的Mg-Al-CO-LDH相比，FeO/Mg-Al-CO-LDH的核壳结构使其具有更好的分散性。无花果蛋白酶对上述LDH纳米片表面，尤其是磁性LDH表面的吸附表现出很强的亲和力，证实磁性FeO/Mg-Al-CO-LDH核结构中FeO的存在使LDH纳米晶壳比原始LDH具有更好的分散性。此外，固定在磁性LDH载体上的酶可通过磁相互作用回收。游离无花果蛋白酶、固定在Mg-Al-CO-LDH和FeO/Mg-Al-CO-LDH上的无花果蛋白酶在120天内的储存稳定性分别损失了约75%、30%和20%的初始活性。
