荧光光谱法研究酸性大红3R与牛血清白蛋白的结合作用

Study on the Interaction between Acid Scarlet Red 3R and Serum Albumin Bovine by Fluorescence Spectrometric Method

在Tris缓冲溶液(pH 7.4)体系中,运用荧光光谱法和紫外光谱法首次研究了染料酸性大红3R(AS)与牛血清白蛋白(BSA)的相互作用,并考察了表面活性剂对体系荧光强度的影响。结果表明,酸性大红3R与牛血清白蛋白能形成基态复合物,从而导致BSA内源荧光猝灭,猝灭机理主要涉及静态猝灭和非辐射能量转移。以实验数据为基础,运用位点模型分别计算得到298 K和308 K时的结合位点数n(0.96和0.92)。运用F rster偶极-偶极非辐射能量转移原理,测定了酸性大红3R与牛血清白蛋白的结合距离r为2.64 nm。根据热力学参数变化确定其主要作用力为静电作用。

The interaction between acid scarlet red 3R （AS） and bovine serum albumin （BSA） in aqueous solution （Tris - HCl buffer, pH 7.4） was studied by fluorescence spectrometric and UV/Vis spectroscopic methods. The effect of surfactants on the interaction between BSA and AS in solution was investigated. The results showed that the fluorescence quenching of BSA by acid scarlet red 3R was a result of the formation of BSA - AS complex,in which both static quenching and non - radioactive energy transferring occurred. According to interaction model, the number of binding site n was calculated to be 0.96 at 298 K and 0.92 at 308 K, respectively. The binding distance r（ r = 2. 64 nm） between acid scarlet red 3 R and BSA was obtained according to the Forster theory of non - radioactive energy. Based on the related thermodynamic parameters analysis, the static interaction between acid scarlet red 3R and BSA was confirmed to be the main binding force.