异黄酮分子与人血清白蛋白的相互作用

Interaction between Isoflavonoid and Human Serum Albumin

通过紫外光谱法、荧光光谱法和圆二色谱法研究了异黄酮类小分子(大豆素和葛根素)与人血清白蛋白的结合常数、结合位点及结合距离等相互作用机制。结果发现在具有相同结合位点的情况下葛根素与人血清白蛋白的结合能力高于大豆素,主要归因于在相同的母核结构上葛根素比大豆素多一个葡萄吡喃糖基,导致反应的结合能力不同。且经过计算得知,异黄酮分子通过形成不发光复合物和F 0··rster能量转移使人血清白蛋白发生静态猝灭。圆二色光谱中葛根素使蛋白质中的α-螺旋含量增加,蛋白结构更加紧密导致蛋白质构象发生变化。研究结果表明:葛根素与人血清白蛋白的特异性结合能力高于大豆素,这对于临床医学、制药学等都具有十分重要的意义。

The mechanisms and binding sites and binding affinity of interaction between isoflavonoid(daidzein and puerarin)and human serum albumin(HSA),respectively,were investigated by Fluorescence,UV-Vis absorption and Circular Dichroism(CD)spectroscopy under simulative physiological conditions.The results showed that the binding affinity between puerarin and HSA was higher than that of daidzein attributed to a glucopyranosyl located in the core aromatic ring structure of puerarin to increase the reaction activity.And The data of fluorescence spectra displayed that the formation of HSA-isoflavonoid complex is a static quenching process.In addition,puerarin binding induced relatively an increased ofα-helix content in HSA than daidzein and make the HSA structure more closely as well as a certain conformation changes,which confirmed by the CD.Our study suggested that puerarin was a ligand for HSA with good affinity and specific binding.The results all has the very vital significance for clinical medicine,pharmaceutics and so on.