摘要
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.mol-1(291 K)和(2.47±0.02)×105 L.mol-1(301 K);根据热力学参数可知,青藤碱与牛血清白蛋白(BSA)相互作用的作用力为氢键和范德华力,青藤碱与牛血清白蛋白间结合距离为r=2.33 nm,只有1个结合位点;牛血清白蛋白的α-螺旋由18.4%降低为15.6%,β-折叠由45.4%上升为74.1%。结论青藤碱对牛血清白蛋白的荧光猝灭机制属于静态荧光猝灭,同步荧光光谱和圆二色性光谱研究结果证实,青藤碱与牛血清白蛋白(BSA)的相互作用可引起牛血清白蛋白的二级结构变化。
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.
出处
《广东药学院学报》
CAS
2011年第6期571-574,共4页
Academic Journal of Guangdong College of Pharmacy
基金
湖北省自然科学基金资助(2001ABB156)
关键词
青藤碱
牛血清白蛋白
荧光光谱
圆二色性光谱
sinomenine
bovine serum albumin
fluorescence spectroscopy
far-UV circular dichroism spectroscopy
