L-半胱氨酸修饰的金纳米粒子与牛血清白蛋白相互作用的荧光光谱研究

Study on Interaction of L-Homocysteine Modified Gold Nanoparticles with Bovine Serum Albumin by Fluorescence Spectroscopy

采用荧光猝灭光谱和同步荧光光谱研究了L-半胱氨酸修饰的金纳米粒子(Cys-GNPs)与牛血清白蛋白(BSA)间的相互作用。根据荧光猝灭相关方程计算了Cys-GNPs与BSA相互作用的结合常数和结合位点数,探讨了其荧光猝灭机制为静态猝灭,并且根据热力学参数确定了二者间的作用力类型,推断出Cys-GNPs和BSA间主要靠疏水作用力结合。同步荧光光谱表明,二者的相互作用没有导致牛血清白蛋白的构象及色氨酸残基的微环境发生明显变化。

The interaction of L-homocysteine （Cys） modified gold nanopartieles with bovine serum albumin （BSA） was studied by fluorescence quenching spectroscopy and synchronous fluorescence spectra. The binding constant and binding sites of L-homoeysteine modified gold nanoparticles to BSA were calculated, respectively, according to the double logarithm regression curve. Fluorescence quenching of BSA by L-homocysteine modified gold nanoparticles was observed, indicating that the quench- ing mechanism is static quenching. In addition, the thermodynamic data show that the key interaction force is hydrophobie inter- action. Finally, the synchronous fluorescence spectra show that the conformation of BSA and the microenvironment of the tryp- tophan have not obviously changed.