Uniform Magnetic Core/Shell Microspheres Functionalized with Ni2+鈥揑minodiacetic Acid for One Step Purification and Immobilization of His-Tagged Enzymes

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• 作者：Yuting Zhang ; Yongkun Yang ; Wanfu Ma ; Jia Guo ; Yao Lin ; Changchun Wang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2013
• 出版时间：April 10, 2013
• 年：2013
• 卷：5
• 期：7
• 页码：2626-2633
• 全文大小：491K
• 年卷期：v.5,no.7(April 10, 2013)
• ISSN：1944-8252

文摘

A facile approach has been developed to synthesize Fe₃O₄/PMG (poly (N,N鈥?methylenebisacrylamide-co-glycidyl methacrylate)) core/shell microspheres using distillation鈥損recipitation polymerization. Treating PMG shell with iminodiacetic acid (IDA) and Ni²⁺ yields composite microspheres of Fe₃O₄/PMG/IDA鈥揘i²⁺. The Ni²⁺ ions loaded on the surface of microspheres provide abundant docking sites for immobilization of histidine-tagged proteins. The high saturation magnetization of Fe₃O₄/PMG (23 emu/g), determined by vibrating sample magnetometer (VSM), allows an easy separation of the microspheres from solution under an external magnetic field. The composite microspheres were used to purify two His-tagged cellulolytic enzymes (Cel48F and Cel9G) directly from crude cell lysates with high binding affinity, capacity, and specificity. The microspheres can be recycled for many times without significant loss of binding capacity to enzymes. The immobilized enzymes on the surface of microspheres well retain their biological activities in degradation of cellulose. These materials show great potential in the biomedical and biotechnological applications that require low-cost purification of recombinant proteins and instant enzyme immobilization at an industrial scale.

Keywords:

Fe₃O₄/PMG core/shell microspheres; purification; His-tagged protein; enzyme immobilization; cellulase; cellulosome