摘要
用共价键合法将青霉素酰化酶固定化在珠状多孔的甲基丙烯酸缩水甘油酯 (GM)共聚物上 ,研究了固定化反应时间、温度、pH值和酶液用量对固定化青霉素酰化酶的表观活性、表观偶联效率、活性回收及稳定性的影响 .将GM共聚物载体加入到磷酸缓冲液 ( 0 1mol L ,pH 10 8)与青霉素酰化酶液 (每克干载体用酶液 1ml)的混合溶液中 ,在 3 0℃下反应 72h ,单位质量 (干重 )固定化酶的表观活性为 3 48U g ,表观偶联效率为 66 7% ,活性回收为 3 1 7% .
Reactive, macroporous and beaded glycidyl methacrylate (GM) copolymer bearing epoxy groups and amide groups was synthesized by inverse suspension polymerization and used as the support for the immobilization of penicillin G amidase (PGA). PGA can be efficiently bound to the epoxy groups in the polymer skeleton. The effects of immobilization conditions such as pH, time, temperature and amount of PGA on the apparent binding efficiency, expression, apparent activity and operational stability of the immobilized enzyme (IME) were investigated. The results show that the properties of IME are markedly influenced by the immobilization conditions. With increasing pH, time and amount of PGA, the apparent activity of IME increases. The immobilization temperature affects the apparent activity of IME and there is a maximum value at 30 ℃. The binding efficiency of PGA increases with increasing pH, temperature and amount of PGA, while the influence of time on it is more complicated. The expression of IME decreases with increasing temperature and amount of PGA, but the effect of pH and time on the expression is just reversed. Operational stability of IMA is independent of pH, temperature and amount of PGA, and affected little by time. The appropriate immobilization conditions of PGA binding on the GM copolymer support are the phosphate buffer 0.1 mol/L, pH 10.8, the temperature 30 ℃, the reaction time 72 h, and the amount of PGA 1 ml/g (dry weight). The apparent activity, apparent binding efficiency and expression of the immobilized enzyme prepared under the above conditions are 348 U/g (dry weight), 66.7% and 31.7%, respectively.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2003年第3期219-223,共5页
