烟碱与牛血清白蛋白相互作用的光谱研究

在0.1 mol·L-1的磷酸氢二钠-柠檬酸体系中，采用荧光光谱、紫外吸收光谱研究了牛血清白蛋白(BSA)与烟碱的相互作用。荧光滴定表明这种相互作用使BSA的内源荧光猝灭，尼古丁和BSA形成1∶1稳定复合物。不同温度和酸度下的猝灭作用证实其静态猝灭行为和疏水作用机制。紫外吸收光谱和同步荧光光谱表明，相互作用引起BSA构象变化，而同步荧光光谱提示结合位点更接近于色氨酸。

Study on the Interaction between BSA and Nicotine

The interaction of BSA and NIC was investigated by absorption spectra, fluorescence spectroscopy and synchronous fluorescence spectroscopy. In the system of sodium phosphate dibasic-citric acid of 0.1 mol(-1) x L(-1), fluorescence titration showed that the fluorescence intensity of BSA at 342 nm was quenched when NIC was added, NIC was capable of binding with BSA to form a 1:1 complex and the quenching mechanism of BSA affected by NIC was shown to be a static quenching procedure by calculating the binding number n and binding constant K. NIC decreased the intensity of the characteristic absorption peak of BSA, showing that the binding of NIC to BSA had strong impact on protein conformation with the decrease in a-helical content of the protein. Synchronous fluorescence indicated that the binding of NIC to BSA is near tryptophan subunit.