锡离子(Ⅳ)与牛血清白蛋白相互作用的研究

Studies on the interaction between Sn(Ⅳ)ion and bovine serum albumin

应用荧光光谱和紫外可见吸收光谱研究了锡离子(Ⅳ)与牛血清白蛋白间的结合作用,确定了锡离子(Ⅳ)对牛血清白蛋白的荧光猝灭过程的猝灭机理。测定了不同温度下该结合反应的结合常数,结合位点数,热力学参数。依据能量转移理论确定了锡离子(Ⅳ)和白蛋白间的结合距离。采用同步荧光技术考察了锡离子(Ⅳ)对牛血清白蛋白构象的影响,并讨论了锡离子(Ⅳ)与白蛋白的结合模式。实验结果表明猝灭机理是动态猝灭,锡离子(Ⅳ)与BSA以物质的量比1∶1的比例结合形成复合物,结合过程主要是熵驱动,相互作用主要为疏水作用力。

The binding between Sn（Ⅳ） and bovine serum albumin（BSA） was investigated by fluorescence spectrum and UV spectrum.It was determinated that quenching mechanism of fluorescence quenching process of Sn（Ⅳ） to bovine serum albumin.The binding constant,the number of binding sites n and thermodynamic parameters were measured at different temperatures by fluorescence quenching method.The binding distance between Sn（Ⅳ） and BSA was also obtained according to Forster theory of non-radiation energy transfer.The effect of Sn（Ⅳ） on the conformation of BSA has also been analyzed using synchronous fluorescence spectroscopy and the binding mode between Sn（Ⅳ）and BSA was discussed.Experimental results showed that the quenching mechanism is dynamic quenching procedure,the complication substance was produced through the binding Sn（Ⅳ）with BSA as 1 ∶ 1,the combined process is mainly driven by entropy,interaction is mainly hydrophobic interaction.