紫外分光光度法测定维拉帕米与牛血清白蛋白相互作用结合常数

Determination of the interaction constant between verapamil and bovine serum albumin by UV spectrophotometry

采用紫外分光光度法对维拉帕米与牛血清白蛋白(BSA)的相互作用进行研究,测定两者的结合常数Kb。实验结果表明,随着药物浓度的增大,蛋白与药物混合溶液的最大吸收波长出现红移,说明两者之间形成了配合物。通过线性拟合求得25℃时,维拉帕米与BSA的Kb值为4.41×10^3M^-1,ΔG为-20.80kJ·mol^-1,ΔH为29.37kJ·mol^-1,ΔS为168.27J·mol^-1。37℃时Kb值为6.98×10^3M^-1,ΔG为-22.82kJ·mol^-1,ΔH为29.37kJ·mol^-1,ΔS为168.27J·mol^-1。热力学参数均表明维拉帕米与BSA之间的结合属自发过程,两者之间的作用力以疏水作用为主。

The interaction between verapamil and bovine serum albumin(BSA)was studied by Ultraviolet spectropotometry(UV).UV scanning was performed at 200~400 nm.The experimental results show that the maximum absorption wavelength of the mixed solution appears a red shift with the increase of the drug concentration indicating the formation of a complex.The K b value,ΔG andΔH were 4.41×10^3 M^-1,-20.80 kJ·mol^-1,29.37kJ·mol^-1,andΔS was 168.27J·mol^-1 at 25℃obtained by linear fitting,respectively.The K b value,ΔG,andΔH were 6.98×10^3M^-1,-22.82kJ·mol^-1,29.37kJ·mol^-1,and 168.27J·mol^-1 at 37℃,respectively.Thermodynamic parameters indicate that the binding between verapamil hydrochloride and BSA is a spontaneous process drove mainly by hydrophobic interaction.