利用共振镜生物传感器研究牛胰脱氧核糖核酸酶Ⅰ与DNA的相互作用

利用共振镜生物传感器研究牛胰脱氧核糖核酸酶Ⅰ与DNA的相互作用 Research of Interaction between Bovine Pancreas DNase Ⅰ and DNA by Resonance Mirror Biosensor 叶茂青 YE Mao-qing 1 2 first-author 潘逆娜 PAN Ni-na 1 2 林爱华 LIN Ai-hua 1 2 秦艺旻 QIN Yi-min 1 2 邹国林 ZOU Guo-lin 1 2 武汉大学生命科学学院 武汉大学生命科学学院 College of Life Sciences, Wuhan University College of Life Sciences, Wuhan University 武汉大学生命科学学院,湖北,武汉,430072 武汉大学生命科学学院,湖北,武汉,430072 利用IAsys共振镜生物传感器研究了牛胰脱氧核糖核酸酶Ⅰ（Bp DNase Ⅰ）与DNA的相互作用.求出了不同温度下,Bp DNase Ⅰ与DNA相互作用的结合和解离的动力学速率常数（Kass,Kdiss）和平衡常数（KA,KD）,并且计算出了该过程的热力学参数（ΔH和TΔS）.在298 K时该结合过程的KA=（3.521 2±0.232 4）×105（mol/L）-1,KD=（2. 852 4±0. 188 3）×10-6 mol/L,TΔS 为（84. 860±3. 712） kJ/mol,该结合过程的ΔH 为（53.222±3.548） kJ/mol,是一个熵驱动的过程.本文还对Mg2+浓度对Bp DNase Ⅰ与DNA的相互作用的影响进行了研究.在相同温度下,Bp DNase Ⅰ与DNA的结合作用在有Mg2+存在时较无Mg2+ 存在时高约30.5 倍,表明Mg2+能极大地提高Bp DNase Ⅰ与DNA的结合能力. A resonance mirror biosensor with a stirred cuvette had been used to monitor the interaction of immobilized bovine pancreas DNaseⅠ（Bp|DNaseⅠ） with calf thymus DNA. The association and dissociation rate constant of the interaction were investigated at different temperatures, and the kinetics data (K ass ,K diss ) and equilibrium data （K A ,K D ） were evaluated. The thermodynamics parameters, changes in enthalpy （ΔH） and entropy （TΔS）, were also evaluated from equilibrium data. At 298 K, the equilibrium data of the interaction were K A =（3.521 2±0.2324）×10 5 （mol/L） -1 ,K D =（2.8524±0.1883） ×10 -6 mol/L, and the TΔS was （84.860±3.712） kJ/mol. The ΔH of the interaction was （53.222±3.548） （kJ/mol,） the results indicated that the interaction process was an entropy driving process. It appears that hydrophobic and electrostatic forces may be both involved in the binding process. We had studied the Mg 2+ influence on the interaction between bovine pancreas DNaseⅠ and DNA. At the same condition, Mg 2+ can remarkably enhance the capacity of bovine pancreas DNaseⅠ associated with DNA. 牛胰脱氧核糖核酸酶Ⅰ 共振镜生物传感器 大分子相互作用 热力学 bovine pancreas DNaseⅠ resonance mirror biosensor macromolecule interaction thermodynamics Q503 国家自然科学基金资助项目（30370366）;高等学校博士学科专项科研基金资助项目 2005-02-01 2021-04-01 2