仿生法制备氧化硅载体固定化苏氨酸脱氨酶及其酶学性质  

Preparation of silica carrier immobilized threonine deaminase by bionic method and its enzymatic properties

作　　者：李巧丽[1] 赵哲[1] 徐建妙[1] 

机构地区：[1]浙江工业大学生物工程学院,浙江杭州310014

出　　处：《生物加工过程》2017年第3期12-17,共6页Chinese Journal of Bioprocess Engineering

基　　金：浙江省公益性项目(2017C33157)

摘　　要：通过共沉淀法制备无机氧化硅载体,然后将其应用到苏氨酸脱氨酶的固定化研究中。用扫描电子显微镜对氧化硅载体进行表征,优化了固定化条件,当n(Si):n(N)为1∶1、偏硅酸浓度为0.03 mol/L、酶添加量为0.16mg/m L时,固定化的效率最高。接着对固定化酶和游离酶的酶学性质进行了考察,结果发现:固定化酶和游离酶的最适pH都是9.0,最适温度都是45℃,而相对于游离酶,固定化酶在pH 9.0~10.0和温度35~50℃范围内稳定性更好。固定化酶的米氏常数为7.48 mmol/L,重复使用15次后,酶活力保持80%以上。说明仿生氧化硅制备的固定化苏氨酸脱氨酶具有酶活回收率高、力学强度高和操作稳定性好等优势。The inorganic silica carrier was prepared by coprecipitation and used to immobilize threonine deaminase. The silica carrier was characterized by scanning electron microscopy. Then immobilization conditions were optimized with n？（Si）： n？（N） at 1 ： 1 , the concentration of silicic acid at 0. 03 mol/ L , the amount of enzyme at 0. 16 mg/mL.The optimal pH of the immobilized enzyme and the free enzyme was both 9. 0 , the optimal temperature was 45℃. Furthermore, the immobilized enzyme was more stable than the free enzyme under the conditions of pH between 9. 0 and 10. 0 , and temperature between 35 and 50℃. The Km value of the immobilized enzyme was 7.48 mmol/ L , and the enzyme activity was maintained at 80% after 15 times of repeated application. The results suggested that the immobilized threonine deaminase prepared by bionic silica has high activity recovery, high mechanical strength and stable operation conditions.

关 键 词：氧化硅 苏氨酸脱氨酶 固定化 酶学性质 纳米材料 

分 类 号：Q814.2[生物学—生物工程]