荧光与紫外光谱法研究柚皮素与人血清白蛋白的结合模式

Study of naringenin and its interaction with HSA by fluorescence and UV spectroscopies

在模拟生理条件下,利用荧光光谱法和紫外吸收光谱法研究了柚皮素(NG)与人血清白蛋白(HSA)的相互作用。实验结果表明,NG对HSA的内源性荧光具有猝灭作用,属于静态猝灭过程。计算了NG-HSA体系的结合常数、结合位点数及反应的热力学参数ΔG,ΔH和ΔS,由此推出二者主要通过氢键和范德华力自发形成了摩尔比为1∶1的非共价复合物。依据Frster非辐射能量转移理论求得二者之间的结合距离为3.41 nm。三维荧光、同步荧光光谱和结合位点取代实验指出,NG主要与HSA的III A亚结构域中site II位点的酪氨酸结合。

The interaction between naringenin （NG） and human serum albumin （HSA） was investigated in the stimulant physiological environment with fluorescence spectrometry and ultraviolet absorption spectrometry. The experimental results indicated that NG had a quench influence on the endogenous fluorescence of HSA, and the fluorescence quenching mechanism was a static quenching procedure. By calculation of the binding constants, the number of binding sites, and the thermodynamic parameters of ΔG, ΔH, ΔS, it＇s deduced that the NG could bind to HSA spontaneously and form a non-covalent complex with the molar ratio of 1 ： 1. The main binding force was hydrogen bond and Van der Waals force. Based on the Forster theory of nonradioactive energy transfer, the binding distance between the two molecules was 3.41 nm. Further more, the combination of three-dimensional fluorescence, synchronous fluorescence spectrometry and competition experiment proved that the main binding sites of HSA with NG was the tyrosine in site Ⅱ, subdomain ⅢA.