摘要
本文研究了磁性壳聚糖固定化转谷氨酰胺酶的最佳条件及固定化酶的酶学性质。以Fe3O4为磁性内核,液体石蜡为分散介质,Span-80为乳化剂,采用反相悬浮包埋法制备了磁性壳聚糖微球,并对其形貌的进行观察,结果显示该载体呈规则的球状、表面平滑,平均粒径为5μm,利于磁性微球在反应体系中的分离和酶的固定。以此磁性壳聚糖微球为载体,戊二醛为交联剂,对转谷氨酰胺酶进行固定化,最佳固定化条件为:戊二醛浓度为1.5%(V/V)、交联时间为5 h、固定时间为1 h、pH条件为6.0,在此条件下,酶活力回收率达到52.4%。经磁性壳聚糖固定化的转谷氨酰胺酶的最适反应温度为50℃,比游离酶高5℃;固定化酶的最适反应pH为8.0,最适pH值向碱性范围移动1.0;固定化酶的热稳定性与游离酶相比有所提高。
Immobilization and enzymological properties of transglutaminase immobilized by a chitosan compound with Fe3O4 as a carrier were investigated in this study.Magnetic chitosan microspheres were prepared by reverse phase suspension process using Fe3O4 as core,paraffin as dispersed medium,Span-80 as emulsifier and epichlorohydrin as cross linking agent.The carrier had well-shaped spherical form with smooth surface,and its mean particle size was 5.0 um.The immobilization of transglutaminase onto magnetic chitosan microspheres by cross-linking with glutaraldehyde was investigated.The optimal immobilization conditions for transglutaminase were： transglutaminase linked with carrier for 1 hour after reacted with 1.5%（V/V） glutaraldehyde for 5 hours in buffer at pH 6.0.Under the optimum conditions,the activity recovery was 52.4%.Moreover,the optimal reaction temperature of immobilized transglutaminase was 50 ℃,being 5 ℃ higher than that of free transglutaminase.The optimal pH of immobilzed transglutaminase was 8.The immobilized enzyme showed higher thermal stability than the free enzymes.
出处
《现代食品科技》
EI
CAS
2011年第9期1081-1083,1095,共4页
Modern Food Science and Technology
基金
国家高新技术研究发展863计划(2008AA10Z303)
关键词
磁性壳聚糖
固定化
转谷氨酰胺酶
magnetic chitosan
immobilization
transglutaminase
作者简介
刘颖（1968-），女，博士，教授，研究方向蛋白质工程
