光谱法研究根皮苷与人血清白蛋白相互作用

Study on Interaction between Phlorizin and Human Serum Albumin by Spectroscopic Methods

在模拟生理条件下,采用荧光光谱、紫外光谱和同步荧光光谱法研究了根皮苷(Phlorizin)与人血清白蛋白(HSA)的相互作用。结果表明:根皮苷能使HSA发生内源荧光猝灭,属静态猝灭。在293、303 K和313 K下,根皮苷与HSA的结合常数分别为3.163 5×105、1.774 8×105、1.193 5×105L.mol-1,结合位点数n近似为1;热力学分析表明根皮苷与HSA间的结合力为氢键及范德华力;根据Frster非辐射能量转移理论求得二者结合距离为3.97 nm;同步荧光光谱表明根皮苷主要与HSA中的色氨酸残基发生相互作用,改变色氨酸周围的局部构象;金属离子的介入会影响根皮苷与HSA的结合能力。

The interaction of phlorizin with human serum albumin（HSA） was studied by fluorescence spectrometry, UV- visible absorption spectrometry and synchronous fluorescence spectrometry. The results showed that phlorizin could induce an endogenous fluorescence quenching of HSA under a mechanism of static quenching. The binding constants were determined to be 3. 163 5 ×10^5 （293 K）, 1. 774 8 ×10^5 （303 K） and 1. 193 5×10^5（313 K） L mol-1, respectively. The binding site（n） was about 1. The thermodynamic parameters suggested that the interaction forces between phlorizin and HSA were mainly hydrogen and vander waals force. The binding distance was estimated to be 3.97 nm according to Ftirster nonradiation energy transfer mechanism. The results of synchronous flu- orescence spectra of phlorizin - HSA system showed that phlorizin mainly interacted with tryptophan in HSA, leading to a local change in protein conformation. In addition, the addition of the common i- ons could affect the binding constant of phlorizin - HSA complex.