Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT) , Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
Preparative Macromolecular Chemistry, Institute for Technical Chemistry and Polymer Chemistry, Karlsruhe Institute of Technology (KIT) , Engesserstrasse 15, 76131 Karlsruhe, Germany.
Biomacromolecules. 2017 Sep 11;18(9):2777-2788. doi: 10.1021/acs.biomac.7b00677. Epub 2017 Aug 15.
Nitrilotriacetic amine (NTA)-functionalized nanoparticles obtained by aqueous polymerization-induced self-assembly (PISA) are introduced as immobilization supports for polyhistidine-functionalized (His-tagged) enzymes. A novel initiator for nitroxide-mediated polymerization based on the nitroxide SG1 and carrying a protected NTA moiety was first synthesized. Size-exclusion chromatography (SEC) and electrospray ionization mass spectrometry (ESI-MS) proved the ability of this initiator to produce well-defined end-functional vinyl polymers. Subsequently, oligo(ethylene glycol) methacrylate-based macroinitiators were synthesized and chain-extended to form amphiphilic block copolymer nanoparticles, either by nanoprecipitation or by PISA. The latter method yielded spherical nanoparticles with a higher definition, as demonstrated by dynamic light scattering (DLS). Deprotection of the NTA moiety and complexation with nickel ions were assessed by DLS and inductively coupled plasma optical emission spectroscopy/mass spectrometry (ICP-OES/MS). Finally, immobilization of His-tagged horseradish peroxidase and ester hydrolase were successfully carried out, leading to catalytically active nanobiocatalysts, as shown by UV-vis measurements.
通过水相聚合诱导自组装（PISA）获得的氮川三乙酸（NTA）功能化纳米粒子被引入作为多组氨酸功能化（His 标记）酶的固定化载体。首次合成了一种基于氮氧自由基 SG1 的新型用于氮氧自由基介导聚合的引发剂，带有保护的 NTA 部分。尺寸排阻色谱（SEC）和电喷雾电离质谱（ESI-MS）证明了该引发剂生产具有明确端基的乙烯基聚合物的能力。随后，合成了基于聚乙二醇甲基丙烯酸酯的大分子引发剂，并通过纳米沉淀或 PISA 进行链延伸以形成两亲嵌段共聚物纳米粒子。后者方法产生了具有更高定义的球形纳米粒子，这一点通过动态光散射（DLS）得到了证明。通过 DLS 和电感耦合等离子体光学发射光谱/质谱（ICP-OES/MS）评估了 NTA 部分的脱保护和与镍离子的络合。最后，成功地进行了 His 标记辣根过氧化物酶和酯水解酶的固定化，如紫外可见测量所示，得到了具有催化活性的纳米生物催化剂。
