摘要
将戊二醛将伴刀豆球蛋白(ConA)和壳聚糖载体交联,然后利用ConA与脲酶糖链的特异性结合作用,实现脲酶的定向固定化。定向固定化的最适条件为戊二醛浓度3.5%、ConA浓度1 mg/mL、ConA溶液pH值7.0、脲酶浓度0.4 mg/mL。定向固定化脲酶的最适pH 5.0～6.0、最适温度77℃、米氏常数Km11.76 mmol/L,与游离酶及非定向固定化脲酶比较,定向固定化脲酶的最适pH向酸性范围发生了偏移并有更宽的pH适用范围,最适温度提高,与底物的亲和力较大,且有较好的操作稳定性。
Concanavalin A （ConA） is immobilized on a pre-activated chitosan microspheres, and then oriented immobilization of urease is carded out based on the strong interaction between ConA and glycoprotein. The optimum immobilization conditions are as follows： glutaraldehyde concentration is 3.5%, ConA concentration 1mg/mL, ConA pH 7.0 and unease concentration 0.4 mg/mL. For orientedly immobilized urease, the highest activity was allowed at pH 5.0-6.0 and temperature 77℃, and the Michaelis constant （Km） was disclosed to be 11.76 mmol/L by Lineweaver-Burk plot. Compared with the free urease and the randomly immobilized urease, the optimum pH of the orientedly immobilized urease becomes smaller and the pH domain wider. Orientedly immobilized urease presents higher temperature resistance, higher affinity to the substrate, and higher stability of operation.
出处
《生物工程学报》
CAS
CSCD
北大核心
2008年第4期617-621,共5页
Chinese Journal of Biotechnology
基金
江苏省自然科学基金项目(No.BK2007051)资助~~
关键词
脲酶
伴刀豆球蛋白
定向固定化
urease, concanavalin A, oriented immobilization
