海洋芽孢杆菌酯酶BSE-1的催化动力学和热失活动力学研究  

Catalytic Kinetics and Inactivation Kinetics of an Esterase BSE-1 from Marine Bacillus sp.

作　　者：高强 郝建华[1] 王跃军[1] 于建生[2] 孙谧[1] 

机构地区：[1]中国水产科学研究院黄海水产研究所,山东青岛266071 [2]青岛科技大学化工学院,山东青岛266042

出　　处：《分子催化》2008年第4期351-355,共5页Journal of Molecular Catalysis(China)

基　　金：国家自然科学基金(30571429);科技部国际重点合作项目(2005DFA30830)

摘　　要：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.The catalytic kinetics and thermal inactivation kinetics of a novel alkaline esterase BSE-1 were studied after it was purified from a marine Bacillus sp.. The survey of effects of metal ions on the enzyme showed that Ca2^＋ activated the enzyme, and the activation effect of Ca2^＋ on the enzyme was found to be of mixed type. Ba^2＋ inhibited the enzyme, the inhibition of Ba^2＋ on the enzyme appeared to be a partial noncompetitive type. The behavior of the enzyme during hydrolysis of PNPP followed Michaelis-Menten kinetics, with gm =8. 15 mmol·L^-l and Vmax=0.97 mmol·mg^-l·min ^-1. In addition, thermal deactivation kinetics of BSE-1 was analyzed by continuous model in the temperature of 70℃. Suitable mechanism was to describe the deactivation process. And the rate constants of the thermal inactivation were k1= 1.41 and k2 =0.28.

关 键 词：海洋芽孢杆菌 酯酶 催化动力学 失活动力学 

分 类 号：O643.32[理学—物理化学]