金刚烷甲酸与牛血清白蛋白相互作用的光谱分析

Spectroscopic analysis of the interaction between 1-Adamantanecarboxylic acid and bovine serum albumin

目的研究金刚烷甲酸(Ad)与牛血清白蛋白(BSA)的相互作用。方法以BSA为荧光剂,Ad为猝灭剂,采用荧光光谱、紫外-可见吸收光谱和圆二色性光谱等方法研究在生理条件下Ad与BSA的相互作用。结果 Ad与BSA二者间的结合常数为7.83×104L.mol-1(291 K),1.59×104L.mol-1(301K);Ad与BSA相互结合时,结合反应的主要作用力为氢键和范德华力,结合距离为r=3.12 nm,结合位点数n=1;BSA的α-螺旋由22.4%降低为19.6%,β-折叠分别由30.2%上升为43.6%。结论 Ad对BSA的荧光猝灭属于静态荧光猝灭;紫外吸收光谱、同步荧光光谱和圆二色性光谱数据证实Ad与BSA相互作用后,BSA的二级结构发生了改变。

Objective To study on the interaction between bovine serum albumin（BSA） and 1-Adamantanecarboxylic acid（Ad）. Methods The interaction of Ad and BSA was observed with fluorescence,UV/vis and Circular Dichroism（CD） Spectroscopy techniques.Results The binding constants KA of Ad with BSA at 291 K and 301 K were（7.83±0.01）×104 L·mol-1 and（1.59±0.01）×104 L·mol-1 respectively.There was only one binding site on BSA for Ad binding.The results indicated that hydrogen bond and Van Der Waals interaction were involved in the binding process.The average binding distance between the donor（BSA） and the acceptor Ad was obtained（r=3.12 nm）.The α-helical structure of BSA reduced from 22.4% to 19.6%,and the β-sheet content increased from 30.2% to 43.6%.Conclusion The experimental results showed that Ad caused the fluorescence quenching of BSA through a static quenching procedure and the binding changes its secondary structure.