青藤碱与牛血清白蛋白相互作用的光谱研究

目的 了解在生理条件下青藤碱与牛血清白蛋白(BSA)的相互作用.方法 采用荧光光谱和圆二色性光谱等方法,研究在生理条件下青藤碱与牛血清白蛋白(BSA)的相互作用.结果 青藤碱与牛血清白蛋白二者间的结合常数(KA)为(9.77±0.01) ×105 L· mo1-1(291 K)和(2.47±0.02)×105 L...

Studies on the interaction between sinomenine and bovine serum albumin by spectroscopy

Objective To investigate the interaction between the physiological protein BSA and sinomenine.Methods The interaction between sinomenine and bovine serum albumin（BSA） was investigated by fluorescence spectroscopy and Far-UV circular dichroism spectroscopy.Results The binding constants KA of sinomenine with BSA at 291 K and 301 K were（9.77±0.01）×105 L·mol-1 and（2.47±0.02）×105 L·mol-1,respectively.Based on the thermodynamic parameters,hydrogen bonding and Van Der Waals interaction play major roles in the binding process.There was only one binding site on BSA for sinomenine.The average binding distance between BSA and sinomenine was obtained（r=2.33 nm）.The α-helical structure of BSA reduced from 18.4% to 15.6%,the β-sheet increased from 45.4% to 74.1%.Conclusion The results showed that sinomenine caused the fluorescence quenching of BSA through a static quenching procedure and that binding of sinomenine to BSA caused a change in its secondary structure.