光谱法研究6-苄氨基嘌呤与牛血清白蛋白的相互作用

Study on the Interaction between 6-Benzylaminopurine and Bovine Serum Albumin by Spectrophotometry

利用荧光光谱法、紫外光谱法、圆二色光谱法等方法研究了6-苄氨基嘌呤(6-BA)与牛血清白蛋白(BSA)之间的相互作用。结果表明,6-BA可以显著猝灭BSA的荧光,其猝灭机制为静态猝灭。6-BA与BSA的结合常数在293K、298 K和308 K时分别为2.4×104L.mol-1、2.6×104L.mol-1和3.1×104L.mol-1,两者之间存在一个结合位点。体系的焓变ΔH和熵变ΔS分别为14.2 kJ.mol-1和132.1 J.mol-1.K-1,说明6-BA与BSA之间主要以疏水作用力相互结合。根据F rster非辐射能量转移理论,6-BA与BSA间的结合距离为2.99 nm、能量转移效率为0.24。紫外光谱和圆二色光谱分析表明,6-BA可以导致BSA构象发生改变。

The interaction between 6-benzylaminopurine（6-BA）and bovine serum albumin（BSA）was investigated by fluorescence,UV absorption and CD spectrometries.A strong fluorescence quenching was observed and the quenching mechanism was considered as static quenching according to the Stern-Volmer equation.The binding constants of 6-BA with BSA at 293 K,298 K and 308 K were obtained as 2.4×104 L·mol-1,2.6×104 L·mol-1 and 3.1×104 L·mol-1,respectively.There was one single binding site between 6-BA and BSA.The thermodynamic parameters enthalpy change（ΔH）and entropy change（ΔS）were calculated as 14.2 kJ·mol-1 and 132.1 J·mol-1·K-1,respectively,which indicated that the acting force between 6-BA and BSA were mainly hydrophobic interactions.According to the Frster non-radiation energy transfer theory,the average binding distance between donor（BSA）and acceptor（6-BA） was obtained（r=2.99 nm）.The investigations of the UV and CD spectra of the system showed that the conformation of BSA was changed in presence of 6-BA.