Department of Chemical Biology and Pharmaceutical Engineering, School of Chemistry and Chemical Engineering, Anhui University of Technology, Ma'anshan, 243002, Anhui, China.
Biochemical Engineering Research Center, Anhui University of Technology, Ma'anshan, 243002, Anhui, China.
Anal Bioanal Chem. 2021 Nov;413(27):6813-6821. doi: 10.1007/s00216-021-03637-5. Epub 2021 Sep 7.
Nano-magnetite with superparamagnetism could be coated by some organic compounds or by nano Au or Pt via surface modifications with multi-step reactions for the applications of isolating histidine-tagged (His-tagged) proteins. Introducing active sites of binding histidine onto the surface of nano-magnetite was the ultimate task. However, multi-step treatments might result in departure of the coatings from the surface of the nano-magnetite, which led to loss of active sites. In this work, we reported a convenient and efficient way of treating nano-magnetites and applied them in isolating His-tagged proteins. Carboxylates were introduced on the surface of home-made nano-magnetite directly via ultrasonic mixing with sodium bitartrate rather than complicated surface modifications, which was proved by thermogravimetric analyses. Ni was, therefore, caught by the carboxylates of the coating via the coordinate interaction, demonstrated by X-ray photoelectron spectra. The coated magnetic nanoparticles with the bonded Ni were successfully employed to selectively bind and separate recombinant His-tagged proteins directly from the mixture of Escherichia coli cell lysate, and showed wonderful affinity for His-tagged proteins with the saturated adsorption amount being 556 mg g. Additionally, such functionalized nano-magnetite manifested the excellent recyclability in isolating His-tagged proteins.
具有超顺磁性的纳米磁铁矿可以通过表面修饰与多步反应，被一些有机化合物或纳米金或纳米铂包覆，从而应用于组氨酸标记（His 标记）蛋白的分离。将结合组氨酸的活性位点引入纳米磁铁矿表面是最终目标。然而，多步处理可能导致涂层从纳米磁铁矿表面脱落，从而导致活性位点的损失。在这项工作中，我们报告了一种方便有效的处理纳米磁铁矿的方法，并将其应用于分离 His 标记的蛋白质。通过与酒石酸钠的超声混合，直接在自制的纳米磁铁矿表面引入羧酸根，而不是复杂的表面修饰，这一点通过热重分析得到了证明。镍通过配位相互作用被涂层的羧酸根捕获，这一点通过 X 射线光电子能谱得到了证明。用结合镍的涂层包覆的磁性纳米粒子成功地用于从大肠杆菌细胞裂解物的混合物中选择性地结合和分离重组 His 标记的蛋白质，并且对 His 标记的蛋白质表现出极好的亲和力，饱和吸附量为 556mg/g。此外，这种功能化的纳米磁铁矿在分离 His 标记的蛋白质方面表现出了优异的可回收性。
