【作者】 王伟； 毛相朝；

【Author】 Wang Wei;Mao Xiangzhao;College of Food Science and Engineering,Ocean University of China;Laboratory for Marine Drugs and Bioproducts,Qingdao National Laboratory for Marine Science and Technology;

【机构】 中国海洋大学食品科学与工程学院； 海洋国家实验室海洋药物与生物制品功能实验室；

【摘要】 本研究开发了一种具有生物相容性的新型磁性甲壳素纳米纤维复合材料(MCNC),并将其作为酶固定化的载体应用于酶的固定化中,选用糜蛋白酶(CT)来衡量其固定化性能。甲壳素通过四甲基哌啶氮氧化物(TEMPO)介导的氧化反应形成甲壳素纳米纤维(CNFs),与磁珠结合完成磁性修饰后形成磁性甲壳素纳米纤维复合材料可用于共价固定酶,通过加入交联剂戊二醛,可进一步提高固定化酶的性能。通过透射电镜和傅里叶变换红外光谱对甲壳素纳米纤维进行表征,结果表明甲壳素被成功制备,且在固定化糜蛋白酶后表现出了杰出的性能。在60℃下孵育3小时后,共价固定和交联固定的糜蛋白酶分别剩余51.6%和70.7%的酶活,而游离糜蛋白酶只剩余29.6%的酶活;在储存20天后,共价固定和交联固定的糜蛋白酶分别剩余85.7%和84.9%的酶活,而游离酶只有18.8%。当在共价固定糜蛋白酶的基础上再使用交联剂进行交联,酶的固定量可增大6.3倍。此外,该磁性甲壳素纳米纤维材料具有良好的顺磁性,可在外加磁场的作用下与反应体系迅速分离。更多还原

【Abstract】 In this study,a novel biocompatible magnetic chitin nanofiber composite(MCNC) was developed as a support for enzyme immobilization,and the enzyme-immobilizing ability was elucidated using chymotrypsin(CT) as a model enzyme.Chitin nanofibers(CNFs) were prepared via 2,2,6,6-tetramethylpiperidine-1-oxyl(TEMPO)-mediated oxidation of chitin and then further modified with magnetic nanoparticles.Glutaraldehyde was used to crosslink the additional CT molecules and aggregate them onto the MCNCs.The CNFs were characterized by transmission electron microscopy,and Fourier transform infrared spectroscopy.The results showed that the CNFs were properly formed and that the CT molecules immobilized on the MCNCs presented excellent properties.After heating the composites at 60 ℃ for 3 h,the non-crosslinked and cross-linked immobilized CTs retained 51.6% and 70.7% of the initial activity,respectively,whereas the free CTs retained only 29.6% of the initial activity.In addition,non-cross-linked and cross-linked immobilized CTs retained 85.7% and 84.9% of the initial activity,respectively,after 20 days,whereas the free CTs retained only 18.8% of the initial activity.When the MCNCs were used to immobilize the CT molecules,the enzyme loading capacity was enhanced up to 6.3-fold upon cross-linking.Moreover,the immobilized CTs could be easily separated and recycled from the reaction system by a magnetic force.更多还原