Department of Chemistry, College of Sciences, Northeastern University, Box 332, Shenyang 110819, China.
Molecules. 2023 Jan 1;28(1):340. doi: 10.3390/molecules28010340.
Glutathione S-transferases (GSTs) are important type-II detoxification enzymes that protect DNA and proteins from damage and are often used as protein tags for the expression of fusion proteins. In the present work, octa-aminopropyl caged polyhedral oligomeric silsesquioxane (OA-POSS) was prepared via acid-catalyzed hydrolysis of 3-aminopropyltriethoxysilane and polymerized on the surface of graphene oxide (GO) through an amidation reaction. Glutathione (GSH) was then modified to GO-POSS through a Michael addition reaction to obtain a GSH-functionalized GO-POSS composite (GPG). The structure and characteristics of the as-prepared GPG composite were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermogravity analysis, and surface charge analysis. The specific binding interactions between glutathione and GST gave GPG favorable adsorption selectivity towards GST, and other proteins did not affect GST adsorption. The adsorption behavior of GST on the GPG composite conformed to the Langmuir isotherm model, and the adsorption capacity of GST was high up to 364.94 mg g under optimal conditions. The GPG-based solid-phase adsorption process was applied to the extraction of GST from a crude enzyme solution of pig liver, and high-purity GST was obtained via SDS-PAGE identification.
谷胱甘肽 S-转移酶（GSTs）是重要的 II 型解毒酶，可保护 DNA 和蛋白质免受损伤，通常用作融合蛋白表达的蛋白标签。在本工作中，通过 3-氨丙基三乙氧基硅烷的酸催化水解制备了八氨丙基笼状多面体低聚倍半硅氧烷（OA-POSS），并通过酰胺化反应在氧化石墨烯（GO）表面聚合。然后通过迈克尔加成反应将谷胱甘肽（GSH）修饰到 GO-POSS 上，得到谷胱甘肽功能化 GO-POSS 复合材料（GPG）。使用扫描电子显微镜（SEM）、傅里叶变换红外光谱（FT-IR）、热重分析和表面电荷分析对所制备的 GPG 复合材料的结构和特性进行了表征。谷胱甘肽和 GST 之间的特异性结合相互作用使 GPG 对 GST 具有良好的吸附选择性，而其他蛋白质不会影响 GST 的吸附。GST 在 GPG 复合材料上的吸附行为符合朗缪尔等温线模型，在最佳条件下 GST 的吸附容量高达 364.94mg g。基于 GPG 的固相吸附工艺被应用于从猪肝粗酶液中提取 GST，并通过 SDS-PAGE 鉴定获得高纯度的 GST。
