文献类型：期刊文献

英文题名：Magnetic Catechol-Chitosan with Bioinspired Adhesive Surface: Preparation and Immobilization of ω-Transaminase

作者：Ni, Kefeng[1];Zhou, Xu[1];Zhao, Li[1];Wang, Hualei[1];Ren, Yuhong[1];Wei, Dongzhi[1]

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

年份：2012

卷号：7

期号：7

外文期刊名：PLOS ONE

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000306507000066)】；

基金：This work was supported by The National Natural Foundation of China (NO.21076079), and Open Funding Project of the State Key Laboratory of Bioreactor Engineering. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

语种：英文

摘要：The magnetic chitosan nanocomposites have been studied intensively and been used practically in various biomedical and biological applications including enzyme immobilization. However, the loading capacity and the remained activity of immobilized enzyme based on existing approaches are not satisfied. Simpler and more effective immobilization strategies are needed. Here we report a simple catechol modified protocol for preparing a novel catechol-chitosan (CCS) - iron oxide nanoparticles (IONPs) composites carrying adhesive moieties with strong surface affinity. The omega-transaminase (omega-TA) was immobilized onto this magnetic composite via nucleophilic reactions between catechol and omega-TA. Under optimal conditions, 87.5% of the available omega-TA was immobilized on the composite, yielding an enzyme loading capacity as high as 681.7 mg/g. Furthermore, the valuation of enzyme activity showed that omega-TA immobilized on CCS-IONPs displayed enhanced pH and thermal stability compared to free enzyme. Importantly, the immobilized omega-TA retained more than 50% of its initial activity after 15 repeated reaction cycles using magnetic separation and 61.5% of its initial activity after storage at 4 degrees C in phosphate buffered saline (PBS) for 15 days. The results suggested that such adhesive magnetic composites may provide an improved platform technology for bio-macromolecules immobilized.