光谱法研究迷迭香酸和牛血清白蛋白的相互作用

利用荧光和圆二色光谱研究了迷迭香酸(RA)与牛血清白蛋白(BSA)之间的相互作用.通过荧光猝灭测得在301、308和315 K时,RA与BSA的结合常数K分别为4.18×10~4、3.62×10~4和2.52×10~4 L/mol,表明RA与BSA间具有较强的结合作用,属于静态猝灭.热力学参数计算结果表明RA与BSA相互作用力以范德华力及氢键作用力为主.圆二色光谱、红外及拉曼光谱、荧光同步光谱研究表明相互作用后BSA的二级结构发生微小变化.此外,常见金属离子对结合有较为显著的影响.

Study on interaction of rosmarinic acid and bovine serum albumin by spectroscopic methods

The interaction between rosmarinic acid (RA) and bovine serum albumin (BSA) was investigated by fluorescence and circular dichroism (CD) spectra at 301,308 and 315 K.By means of the fluorescence quenching method,the binding constants K were determined to be 4.18×10~4,3.62×10~4 and 2.52×10~4 L/mol,respectively,indicating that the binding of RA to BSA was strong,and the quenching mechanism was a static quenching.The enthalpy change (ΔH) was calculated to be -28.57 kJ/mol and the entropy change (ΔS) was -20.51 J·mol~(-1)·K~(-1) The hydrogen interaction played a major role between the tryptophan (212) residue of BSA and the RA,but the van der Waals force mostly existed between the molecules of BSA and RA during the binding process.The secondary structure of BSA was altered slightly after RA bound to BSA as evidenced by the CD,FT-IR and Raman spectroscopic results.In addition,the common metal ions had also influenced the binding of RA to BSA.