阿托伐他汀钙与牛血清白蛋白的相互作用

采用电化学方法并结合紫外、红外光谱分析, 研究了近生理pH 实验条件下新型抗血脂紊乱药物阿托伐他汀钙(AC)与牛血清白蛋白(BSA)的相互作用, 探讨了BSA对AC峰电流的增敏和减敏效应. 实验发现, 在pH为7.17的NaH₂PO₄-Na₂HPO₄缓冲溶液中, AC在静汞电极上产生一个还原峰, 加入BSA后峰电位发生移动且峰电流发生变化. 电化学研究结果表明, 部分疏水性AC小分子的芳香基团通过疏水作用镶嵌到BSA疏水微区内部, 使AC与BSA之间通过疏水作用力形成一种1:1的结合物, 结合常数为1.67×10⁵. 紫外吸收光谱结果表明,AC的加入使BSA的紫外吸收峰发生红移且有减色效应, 导致BSA 构象改变、α-螺旋含量减小. 红外光谱结果显示, AC与BSA分子中氨基酸残基的硫及氮原子形成键合作用.

Interaction between Atorvastatin Calcium and Bovine Serum Albumin

The interaction between atorvastatin calcium (AC) and bovine serum albumin (BSA) was investigated using electrochemical techniques in conjunction with spectroscopy. Both enhancement and abatement actions of BSA on the peak current of AC were discussed in low and high BSA concentration ranges. In pH 7.17 phosphate buffer solution, AC caused an irreversible reduction peak on mercury electrode. With the addition of BSA into the AC solution, the peak current of AC changed and peak potential shifted. The results of linear-sweep voltammetry showed that the molecule of BSA came into being the hydrophobic tiny section where hydrophobic aromatic-group in AC molecule was embedded through hydrophobic interaction when the concentration of BSA was in the range from 1.0×10^-7 to 2.0×10^-6 mol·L^-1. The binding equilibrium constant and binding ratio were calculated as 1.67×10⁵ and 1:1, respectively. Furthermore, the results of UV absorption spectra showed that the UV absorption peak of BSA could red-shift slightly in the presence of AC. The interaction between AC and BSA could result in the change of conformationof BSA. Thus, α-helix structure in BSA was also decreased. The results of IR spectroscopy showed that AC could interact with sulfur-containing and nitrogen-containing groups in BSA molecular.