荧光光谱法研究咖啡因与肌红蛋白的相互作用  

Study on Interaction of Caffeine with Myoglobin by Fluorescence Spectroscopy

作　　者：黄鹤勇[1,2] 顾晓天[3] 丁艳[2] 周家宏[3,1] 冯玉英[3,1] 

机构地区：[1]江苏省生物功能材料重点实验室,江苏南京210097 [2]南京师范大学化学与环境科学学院,江苏南京210097 [3]南京师范大学分析测试中心,江苏南京210097

出　　处：《光谱学与光谱分析》2009年第10期2798-2802,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(20603018);江苏省科技发展计划项目(BM2007132)资助

摘　　要：采用荧光光谱法在生理pH7.4条件下研究了药物咖啡因与肌红蛋白分子间的相互作用,表明这种相互作用能使肌红蛋白的内源荧光猝灭。通过猝灭常数,结合常数和结合位点数的计算,证明此猝灭为静态猝灭机制。咖啡因和肌红蛋白形成1∶1稳定配合物,形成常数(18℃)KA=1.82×104L.mol-1;根据热力学参数确定了它们之间的主要作用力为疏水力和静电力。利用同步荧光光谱法研究了咖啡因对肌红蛋白构象的影响。咖啡因能使肌红蛋白的构象发生改变,导致蛋白质分子中色氨酸和酪氨酸残基所处微环境由原来的疏水环境不同程度地向亲水环境转变。The interaction of caffein and myoglobin was investigated by fluorescence spectroscopy and synchronous fluorescence spectroscopy. The intrinsic fluorescence of myoglobin was significantly quenched by caffein under the physiological condition （pHT. 4） . The results indicated that caffeine was capable of binding with myoglobin to form a 1 ： 1 complex and the quenching mechanism of myoglobin affected by caffeine was shown to be a static quenching procedure by calculating quenching constant, binding sites and binding constant. According to the thermodynamic parameters, the main binding force of the interaction is electrostatic force and hydrophobic force. The change in the micro-circumstance of aminos of myoglobin was analyzed by synchronous fluorescence spectrometry. The result indicated that caffeine can change the conformation of the protein, leading to the change in the micro-environment of tryptophane and tyrosine residues from hydrophobic environment to hydrophilic environment to different extent.

关 键 词：咖啡因 肌红蛋白 荧光光谱 

分 类 号：O657.3[理学—分析化学]