Di-functional magnetic nanoflowers: A highly efficient support for immobilizing penicillin G acylase
Di-functional magnetic nanoflowers: A highly efficient support for immobilizing penicillin G acylase
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双功能磁性纳米花：固定青霉素G酰化酶的高效载体
DOI：
10.1002/jccs.201900559
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发表时间：
2020
影响因子：
1.8
通讯作者：
Hu Chunmiao
中科院分区：
文献类型：
--
作者：
Zheng Zhaoyu;Xue Ping;Li Peng;Shi Keren;Zhang Weiwei;Hu Chunmiao
采用扫描电子显微镜、透射电子显微镜(TEM)、振动样品磁强计、N-2吸附等手段对新型双功能磁性纳米花(DMNF)进行了表征，该磁性纳米花同时具有环氧基团和亲水性儿茶酚以及邻苯二醌基团，能够与青霉素G酰化酶(PGA)共价偶联。研究表明，DMNF具有“分层花瓣”结构的纳米片，比饱和磁化强度为39.7 emu/g，平均孔径为25.4 nm，比表面积为17.28 m(2)/g。在酶载量为 106 mg/g 的 DMNF 上固定的 PGA 催化水解青霉素 G 钾时，表观活性达到 2,667 U/g，这得益于磁性 DMNF 的“分层花瓣”和大孔结构导致高酶载量和底物分子快速扩散到固定化 PGA 中进行反应。重复使用10个循环后，固定化PGA的表观活性仍能保持2,408 U/g（初始活性的90%以上）。由于PGA的氨基与DMNF上的环氧基、儿茶酚和邻苯二醌基团的反应基团的共价相互作用，酶分子在支持物之间发生共价偶联，因此磁性固定的PGA表现出优异的操作稳定性。此外，通过使用 DMNF 固定，PGA 显示出良好的耐酸碱性以及热稳定性。
The novel di-functional magnetic nanoflowers (DMNF) which had both epoxy groups and hydrophilic catechol as well as phthaloquinone groups capable of covalently coupling of penicillin G acylase (PGA) were characterized by scanning electron microscopy, transmission electron microscope (TEM), vibrating sample magnetometer, N-2 adsorption, and so on. The studies showed that DMNF possessed "hierarchical petal" structure of nanosheets had specific saturation magnetization of 39.7 emu/g and average pore diameter of 25.4 nm as well as specific surface area of 17.28 m(2)/g. For hydrolysis of penicillin G potassium catalyzed by the PGA immobilized on DMNF with enzyme loading of 106 mg/g-support, its apparent activity reached 2,667 U/g, which benefited from the "hierarchical petal" and large pore structure of the magnetic DMNF leading to high enzyme loading and fast diffusion of substrate molecules to the immobilized PGA to reaction. The apparent activity of the immobilized PGA could keep 2,408 U/g (above 90% of its initial activity) after repeating use for 10 cycles. The magnetic immobilized PGA exhibited excellent operational stability due to covalently coupling of the enzyme molecules between the support by covalent interaction of the amino groups of PGA and the reactive groups of epoxy, catechol, and phthaloquinone groups on DMNF. Furthermore, the PGA displayed good acid and alkaline resistance as well as thermal stability by immobilization using DMNF.