萘酰亚胺类抗肿瘤药物与牛血清白蛋白相互作用的研究

Study on the Interactions between Naphthalimide-based Anti-tumor Drugs and Bovine Serum Albumin

采用荧光光谱、位点竞争和圆二色谱等实验方法在模拟人体生理条件下研究了三种萘酰亚胺类抗肿瘤药物(NADs)与牛血清白蛋白(BSA)之间的相互作用。荧光猝灭结果表明NADs对BSA的猝灭机制均为静态猝灭。由热力学参数ΔS>0,ΔH<0可知疏水作用力是NADs与BSA之间结合的主要作用力,但氢键和范德瓦尔斯力不可忽略。位点竞争实验结果显示NADs与BSA的结合部位均在BSA的SiteⅠ位。圆二色谱研究结果表明三种药物均使BSA的α-螺旋含量减少,即BSA的二级结构发生了改变。

The interactions between naphthalimide-based anti-tumor drugs （NADs） and bovine serum albumin （BSA） were investigated by fluorescence spectroscopy, site marker competitive experiments and circular dichroism under simulative physiological conditions. The result of fluorescence quenching spectroscopy showed the quenching mechanisms of NADs were static. The relative thermodynamic parameters of the van＇t Hoff equation indicated that hydrophobic force was the predominant intermolecular force in the bind- ing of NADs to BSA, while van der Waals interactions and hydrogen bonds could not be ignored. The site marker competitive experiments confirmed all the binding sites of NADs to BSA were located in site I . The circular dichroism spectra demonstrated that the presence of NADs decreased the a-helical content of BSA and suggested the change of the secondary structure of BSA.