论文部分内容阅读
海洋芽孢杆菌发酵产生的酯酶BSE-1经分离纯化后,以对硝基苯磷酸酯(PNPP)为底物,对电泳纯BSE-1的催化性质、催化动力学和热失活动力学进行了研究.催化动力学研究表明,金属离子对BSE-1的活性影响显著,其中Ca2+的激活作用最强,为混合型激活作用;而Ba2+的抑制作用最为明显,为非竞争性抑制作用.BSE-1的酶促反应动力学符合米氏方程,其中Km=8.15mmol·L-1,Vmax=0.97mmol·mg-1·min-1.采用连续模型对BSE-1在70℃的热失活动力学进行模拟,求得酶的失活速率常数k1=1.41,k2=0.28.
After isolation and purification of esterase BSE-1 produced by Bacillus subtilis, the catalytic properties, catalytic kinetics and thermal inactivation kinetics of pure BSE-1 were studied by using p-nitrophenyl phosphate (PNPP) as substrate Studies on catalytic kinetics showed that metal ions had a significant effect on the activity of BSE-1, of which Ca2 + had the highest activation and mixed activation, while Ba2 + had the most obvious inhibitory effect on non-competitive BSE- 1 Km = 8.15mmol·L-1, Vmax = 0.97mmol · mg-1 · min-1. The kinetics of thermal inactivation of BSE-1 at 70 ℃ with a continuous model The simulation results showed that the enzyme inactivation rate constant k1 = 1.41, k2 = 0.28.