荧光光谱法研究芥子碱与人血清蛋白的相互作用

摘要

在模拟生理条件下（pH=7.4），采用荧光光谱法研究了芥子碱与人血清蛋白（HSA）的相互作用。结果表明芥子碱可以使人血清蛋白的内源荧光发生猝灭。根据 Stern-Volmer 方程计算得到不同温度下的荧光猝灭常数，在296～303 K 温度范围为静态猝灭，303~310 K 为动态猝灭；由 Lineweaver-Burk 双倒数方程得出不同温度下芥子碱和 HSA的结合常数（Ka）和结合位点数（n），并计算得到其荧光猝灭的吉布斯自由能（ G）和熵值（ S），其结果表明芥子碱与人血清蛋白的作用过程是一个熵增加、自由能降低的自发反应。在296~303 K 时两者凭借氢键和范德华力进行结合，在303~310 K 温度范围两者的主作用力为疏水作用。%　　Interaction between sinapine and human serum albumin (HSA) were studied by fluorescence quenching spectroscopy at simulated physiological condition (pH=7.4). Results showed that sinapine could make a human serum albumin protein fluorescence quenching. The quench constant was calculated according to Stern-Volmer equation, indicating the process was static quench at temperature range of 296~303 K, and turned to dynamic quenching at temperature range of 303~310 K. Binding sites(n)and binding constant(Ka)were deduced between sinapine and human serum albumin through Lineweaver-Burk equation and calculated Gibbs free energy( G) and Entropy( S), indicating that the reaction process between sinapine and human serum albumin was a entropy increasing, free energy decreasing spontaneous reaction. The main bonding formation of system was hydrogen and Van Der Waals force at the temperature range of 296~303 K, and after changed into hydrophobic force when the temperature stepped up to 303~310 K.