Shen Ying, Guo Wei, Qi Li, Qiao Juan, Wang Fuyi, Mao Lanqun
Beijing National Laboratory of Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, No. 2 Zhongguancun Beiyijie, Beijing 100190, China.
J Mater Chem B. 2013 May 7;1(17):2260-2267. doi: 10.1039/c3tb20116c. Epub 2013 Mar 15.
The effort to stabilize enzymes and improve their activity has generated great interest because of their wide application in proteomics research, bioenergy conversion, bioassays and so on. In this work, biocompatible reactive polymer, poly (glycidyl methacrylate), grafted from magnetic nanoparticles by atom transfer radical polymerization method, has been firstly proposed to immobilize enzymes for microwave-assisted digestion. Meanwhile, trypsin was chosen as a model enzyme. Resulting from the increased functionality, the immobilization amount of the enzyme on the magnetic nanoparticle surface has been greatly improved. Furthermore, the enzyme immobilized magnetic nanoparticles have exhibited excellent repeatability and stability. The influence of the polymer chain length on digestion efficiency has been investigated both at 37 °C and under microwave. It has been found that the digestion efficiency increases with the lengthened polymer brushes due to the increased immobilization amount. Utilizing cytochrome C as a model protein for digestion, the performance of this immobilized biocatalyst has been demonstrated and this digestion assisted with microwave could be completed within 15 s. This study offers insight into the design of polymer brushes on the surface of magnetic nanoparticles for high digestion efficiency in the future.
由于酶在蛋白质组学研究、生物能源转化、生物测定等方面的广泛应用，稳定酶并提高其活性的研究引起了广泛关注。在这项工作中，首次提出通过原子转移自由基聚合法将生物相容性反应性聚合物聚（甲基丙烯酸缩水甘油酯）接枝到磁性纳米颗粒上，用于固定酶以进行微波辅助消化。同时，选择胰蛋白酶作为模型酶。由于功能的增加，酶在磁性纳米颗粒表面的固定量得到了极大提高。此外，固定化酶的磁性纳米颗粒表现出优异的重复性和稳定性。研究了聚合物链长度在37℃和微波条件下对消化效率的影响。结果发现，由于固定量增加，消化效率随着聚合物刷的延长而提高。以细胞色素C作为消化的模型蛋白，证明了这种固定化生物催化剂的性能，并且这种微波辅助消化可以在15秒内完成。这项研究为未来设计磁性纳米颗粒表面的聚合物刷以实现高效消化提供了思路。
