Cu2+对香豆素与BSA相互作用的影响

采用荧光光谱法研究了Cu^2＋对香豆素类中药有效成分的母核化合物香豆素与牛血清白蛋白（BSA）相互作用的影响．实验结果表明，有Cu^2＋存在时，香豆素对BSA内源荧光的猝灭过程是以静态猝灭为主，香豆素与BSA结合过程的表观结合常数KA数值为lO^4量级，结合位点数n的范围为2．9～3．4，香豆素-BSA的分子间相互作用力类型仍是以疏水作用为主，熵增加是该作用过程的主要热力学驱动因素；与不合Cu＾２＋的相比，香豆素对BSA内源荧光的静态猝灭常数KP、表观结合常数KA都明显增大，但结合位点数和分子间作用力类型没有明显改变，表明Cu＾2＋可能参与了香豆素与BSA的结合过程．

Effect of Cu2+ on the Interaction Between Bovine Serum Albumin and Coumarin

The effect of Cu~(2+) on the interaction between bovine serum albumin(BSA) and coumarin was investigated mainly by means of fluorescence spectroscopy.The experimental results showed that in the presence of Cu~(2+),the type of BSA intrinsic fluorescence quenching by coumarin is mainly static quenching.The magnitude of the apparent association constant K_A in coumarin-BSA binding process is about 10~4 and the number of binding sites of coumarin on BSA is within the range of 2.9~3.4.The main driving force in coumarin-BSA interactional process is hydrophobic force,thereby the increase in entropy is the primary thermodynamic driving factor.While compared with those parameters in the absence of Cu~(2+),the static quenching constant(K_P) and K_A are higher than those in absence of Cu~(2+),however,the number of binding sites of coumarin on BSA and the main driving force in coumarin-BSA binding process are not changed evidently.Therefore,it is estimated that Cu~(2+) is likely to participate in the interaction between coumarin and BSA.