光谱法研究高铁肌红蛋白活性中心与咪唑的配位反应  

Spectral Study on Coordination Reaction between MetMb and Imidazole

作　　者：周华伟[1] 曹洪玉[2,1] 唐乾[2,1] 李进京[2] 郑学仿[2,1] 

机构地区：[1]辽宁省生物有机化学重点实验室,大连116622 [2]大连大学生物工程学院,大连116622

出　　处：《无机化学学报》2011年第3期445-450,共6页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.20871024);辽宁省高校创新团队项目(No.2006T002;2008T005;2009T003);辽宁省教育厅项目(No.2009A069;2009A071);大连市科技计划项目(No.2008E11SF170)资助

摘　　要：采用紫外-可见(UV-Vis)、常规荧光、同步荧光等光谱法研究了高铁肌红蛋白(metMb)与咪唑的轴向配位反应的光谱性质。结果表明,metMb-咪唑配位体系的形成使得metMb的Soret带和Q带均发生红移;并对7位和14位2个Trp残基微环境极性的影响是不同的;同时还引起metMb活性中心铁卟啉597 nm处荧光增强,并且体系荧光强度与加入咪唑的浓度成线性关系,由此计算了不同温度下反应的配位数、结合常数及热力学参数;metMb与咪唑配体之间的配位反应是按物质的量比1∶1进行的;温度升高不利于配位反应的进行;热力学参数表明,此配位反应是自发进行的,焓变是整个配位反应的主要动力。The spectroscopic properties of coordination reaction between metMb and imidazole were investigated by means of UV-Vis absorption spectra,fluorescence spectra,and synchronous fluorescence spectra.The experimental results showed that the transitions of Soret and Q band shifted to lower energies due to the formation of metMb-imidazole complex;effect of the formation of metMb-imidazole complex on Trps at position 7 and 14 were different;the equation for calculating the binding constant of imidazole to metMb was introduced based on the relationships between the fluorescence enhancement of heme at 597 nm and the concentration of imidazole.According to the fluorescence enhancement equation,the binding constants of the complex at different temperatures and the thermodynamic parameters at corresponding temperatures were obtained.The coordination reaction was carried out in a molar ratio of 1∶1.The association constant would decrease with increasing temperature,which was a disadvantage factor for the reaction.The thermodynamic parameters revealed that the driving force of the coordination reaction was the change of enthalpy.

关 键 词：高铁肌红蛋白 咪唑 配位反应 热力学参数 荧光光谱 

分 类 号：O629.73[理学—有机化学]