碳纳米管存在下盐酸胺碘酮与BSA的相互作用

Interaction of amiodarone hydrochloride with BSA in the presence of carbon nanotubes

在pH 7.40的Tris-HCl缓冲体系下,用荧光光谱法研究了碳纳米管(MCNTs)对盐酸胺碘酮(AD)和牛血清白蛋白(BSA)荧光光谱特性的影响以及无碳纳米管共存时盐酸胺碘酮与BSA之间的相互作用。结果表明,AD对BSA的荧光有较强的猝灭作用,其猝灭机理为动态猝灭。碳纳米管的存在使AD对BSA的猝灭作用增强。计算了不同温度下AD与BSA之间的表观结合常数KA,结合位点数n。相应的热力学参数ΔH、ΔG和ΔS表明,AD与BSA之间主要以静电作用力结合。根据Frster非辐射能量转移理论,确定了AD与BSA之间的结合距离r=3.99 nm。此外,利用同步荧光光谱,分析了AD对BSA构象的影响。在碳纳米管存在下,AD与BSA结合位点数增加,其结合常数也高于无MCNTs时的KA值,MCNTs的加入没有引起BSA构象的变化。

Under the pH 7.40 Tris-HCl buffer system,fluorescence spectroscopy was used to investigate the influences of carbon nanotubes（CNTs）on the fluorescence of amiodarone hydrochloride（AD）on bovine serum albumin（BSA）and the influences of AD on that of BSA without CNTs.The experimental results demonstrated that AD could quench the intrinsic fluorescence of BSA,and the quenching mechanism was dynamic quenching.The fluorescence quenching action of AD on BSA was strengthened in the presence of CNTs.The binding constants KA,binding sites n and the corresponding thermodynamic parameters ΔH,ΔG and ΔS at different temperatures were calculated.Based on the thermodynamic parameters,it was proved that the major roles of binding force of AD-BSA was the electrostatic.The distance r of AD-BSA was evaluated according to the theory of Fster energy transfer.Moreover,the effect of AD on the conformation of BSA was also analyzed by using synchronous fluorescence spectroscopy.The results showed that AD changed the conformation of BSA during the reaction.But the CNTs could not change the conformation of BSA.The binding constants KA,binding sites n of AD on BSA was increased in the presence of CNTs.The discussion offer a reference study on the action mechanism of CNTs and AD with albumin in vivo.