离子液体对重组β-葡萄糖醛酸苷酶催化特性的影响  

The Catalytic Characteristics of β-glucuronidase in Systems Containing Ionic liquids

作　　者：陈金燕[1] 刘桂艳[2] 李春[1,2] 

机构地区：[1]石河子大学化学化工学院/新疆兵团化工绿色过程重点实验室-省部共建国家重点实验室培育基地,石河子832003 [2]北京理工大学生命学院,北京100083

出　　处：《石河子大学学报（自然科学版）》2011年第5期603-607,共5页Journal of Shihezi University(Natural Science)

基　　金：国家自然科学基金项目(20976014);教育部博士点基金项目(20091101110036);北京市自然科学基金项目(2112035)

摘　　要：研究了重组β-葡萄糖醛酸苷酶分别在含疏水性离子液体1-丁基-3-甲基咪唑六氟磷酸盐([Bmim]PF6)和亲水性离子液体1-丁基-3-甲基咪唑四氟硼酸盐([Bmim]BF4)的体系中催化4-硝基苯基-β-D-吡喃半乳糖苷(pNPG)生成对硝基苯酚(pNP)的反应,并以缓冲液单相反应体系作为对照,考察离子液体对酶催化反应特性的影响。结果显示:[Bmim]PF6/缓冲液两相体系中最适底物浓度为10.0mmol/L,较缓冲液单相体系提高了1倍,确定了该体系动力学与热力学参数Vmax为0.153mmol/(L·min),Km为0.773mmol/L,表观活化能Ea为35.386kJ/mol;而缓冲液单相反应体系中Vmax为0.094mmol/(L·min),Km为0.620mmol/L,Ea为48.199kJ/moL,说表明离子液体[Bmim]PF6降低了反应活化能并提高了反应速率。The hydrolysis of P-Nitrophenyl beta-D-Galactopyranoside（pNPG） to P-Nitrophenyl（pNP） catalyzed by β-glucuronidase in system containing 1-butyl-3-methylimidazolium hexafluorophosphate（PF6） or 1-butyl-3-methylimidazolium tetrafluoroborate（BF4） were performed.The reactions in PF6/buffer biphasic system were mainly studied,and with the buffer single-phase system as control.The optimal conditions of reaction in PF6/buffer biphasic system were determined,the optimum ionic liquid concentration,buffer pH,substrate concentration,temperature were 40%,4.8~6.2,10.0 mmol/L,35~50 °C,respectively.The kinetics and thermodynamics parameters were as follows in PF6/buffer biphasic system：Vmax=0.153 mmol/（L·min）,Km=0.773 mmol/L.The activation energy of hydrolyzing of pNPG in PF6/buffer biphasic system is 35.386 kJ/moL,and in monophasic buffer system is 48.199 kJ/moL.

关 键 词：离子液体 Β-葡萄糖醛酸苷酶 催化特性 两相体系 

分 类 号：Q814.9[生物学—生物工程]