Research Institute for Chemical Process Technology, National Institute of Advanced Industrial Science and Technology (AIST), 4-2-1 Nigatake, Miyagino-ku, Sendai, Miyagi 983-8551, Japan.
Research Institute for Chemical Process Technology, National Institute of Advanced Industrial Science and Technology (AIST), 4-2-1 Nigatake, Miyagino-ku, Sendai, Miyagi 983-8551, Japan.
J Biosci Bioeng. 2021 Mar;131(3):250-255. doi: 10.1016/j.jbiosc.2020.10.012. Epub 2020 Nov 13.
A novel organic-inorganic hybrid porous material (KCS-2), containing both lipophilic and hydrophilic nanospaces to mimic a lipid bilayer, was utilized as an immobilization support and reaction accelerator for glutamate decarboxylase (GADβ). Upon evaluation of the adsorption of GADβ on KCS-2, the amount of immobilization was found to be approximately four times higher than that on non-porous silica, and a comparable adsorbability to mesoporous silica was observed. Following γ-aminobutyric acid (GABA) production by the decarboxylation of l-glutamic acid using these immobilized enzymes, the enzymatic activity of the GADβ-KCS-2 composite was found to be significantly higher than that of the free enzyme. In contrast, the activity of the more common GADβ-mesoporous silica composite decreased. Furthermore, the enzymatic activity of the GADβ-KCS-2 composite was superior to those of the un-immobilized free enzyme and the amorphous material itself over a wide temperature range. Thereby, these findings suggest that the amphiphilic nanospace of KCS-2 is suitable as a stable enzyme immobilization field and reaction acceleration field under such conditions. In addition, the durability of the immobilized enzyme was examined in terms of GABA production, with approximately 20% activity retention being observed after 10 cycles using KCS-2. Such durability was not observed for the non-porous silica material due to enzyme desorption.
一种新型的有机-无机杂化多孔材料（KCS-2），包含亲脂和亲水纳米空间，以模拟脂质双层，被用作谷氨酸脱羧酶（GADβ）的固定化载体和反应加速剂。在评估 GADβ在 KCS-2 上的吸附时，发现固定化量约为非多孔硅的四倍，并且与中孔硅的吸附能力相当。在用这些固定化酶进行 l-谷氨酸脱羧生成 γ-氨基丁酸（GABA）后，发现 GADβ-KCS-2 复合物的酶活性明显高于游离酶。相比之下，更为常见的 GADβ-中孔硅复合物的活性降低了。此外，在较宽的温度范围内，GADβ-KCS-2 复合物的酶活性优于未固定的游离酶和无定形材料本身。因此，这些发现表明，KCS-2 的两亲纳米空间适合作为在这种条件下稳定的酶固定化场和反应加速场。此外，还考察了固定化酶在 GABA 生产方面的耐久性，使用 KCS-2 进行 10 次循环后，观察到约 20%的活性保留。由于酶解吸，非多孔硅材料没有观察到这种耐久性。
