文献类型：期刊文献

英文题名：Enhancement of the activity of enzyme immobilized on polydopamine-coated iron oxide nanoparticles by rational orientation of formate dehydrogenase

作者：Gao, Xin[1];Ni, Kefeng[1];Zhao, Chengcheng[1];Ren, Yuhong[1];Wei, Dongzhi[1]

机构：[1]E China Univ Sci & Technol, Shanghai Collaborat Innovat Ctr Biomfg Technol, New World Inst Biotechnol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China

年份：2014

卷号：188

起止页码：36

外文期刊名：JOURNAL OF BIOTECHNOLOGY

收录：;EI(收录号：20143618139653);WOS:【SCI-EXPANDED(收录号:WOS:000344183700006)】；

基金：This work was funded by the National Natural Foundation of China (No. 21076079), National Special Fund for State Key Laboratory of Bioreactor Engineering (2060204), and the Fundamental Research Funds for the Central Universities and National Major Science.

语种：英文

外文关键词：Directional immobilization; Site-directed mutagenesis; Formate dehydrogenase; Iron oxide nanoparticles; Polydopamine

摘要：Immobilization of enzymes onto nanoparticles and retention of their structure and activity, which maybe related to the orientation of enzymes on nanoparticles, remain a challenge. Here, we developed a novel enzyme-orientation strategy to enhance the activity of formate dehydrogenase immobilized on polydopamine-coated iron oxide nanoparticles via site-directed mutation. Seven mutants were constructed based on homology modeling of formate dehydrogenase and immobilized on polydopamine-coated iron oxide nanoparticles to investigate the influence of these mutations on immobilization. The immobilized mutant C242A/C275V/C363V/K389C demonstrated the highest immobilization yield and retained 90% of its initial activity, which was about 3-fold higher than that of wild-type formate dehydrogenase. Moreover, co-immobilization of formate dehydrogenase and leucine dehydrogenase was performed for the synthesis of L-tert-leucine. The catalytic efficiency of the co-immobilized mutant C242A/C275V/C363V/K389C and leucine dehydrogenase increased by more than 4-fold compared to that of co-immobilized wild-type formate dehydrogenase and leucine dehydrogenase. (C) 2014 Elsevier B.V. All rights reserved.