蛇床子素与人血清白蛋白相互作用的光谱学特征

在模拟人体生理条件下,应用荧光光谱法、紫外-可见光谱法、傅里叶变换红外光谱(FT-IR)法以及圆二色谱(CD)法,研究了蛇床子素(osthole)与人血清白蛋白(HSA)的相互作用。结果表明,蛇床子素通过与HSA形成基态复合物使其内源荧光猝灭。计算出的热力学参数焓变(ΔH)和熵变(ΔS)值表明,疏水作用力是蛇床子素-HSA结合的主要驱动力。位点竞争实验表明,蛇床子素主要结合在HSA的siteⅢ位。根据Frster非辐射能量转移理论计算出蛇床子素在HSA中的结合位置与色氨酸残基间的距离为3.99nm。红外变换光谱和圆二色谱分析显示,蛇床子素的存在诱导HSA的二级结构发生了部分改变。

Spectroscopic studies of interaction between osthole and human serum albumin

The interaction between osthole and human serum albumin(HSA) was investigated by fluorescence,UV-vis absorption,Fourier transform infrared(FT-IR) and circular dichroism(CD) spectroscopy under simulative physiological conditions.The results suggested that the intrinsic fluorescence of HSA was quenched by osthole was probably a result of the formation of osthole-HSA complex.The calculated thermodynamic parameters indicated that the binding of osthole to HSA was driven mainly by hydrophobic interaction.The site markers competitive experiments revealed that the binding of osthole to HSA mainly took place in site Ⅲ.The binding distance between osthole and HSA was determined to be 3.99nm based on the Frster theory.The results of FT-IR and CD spectra showed that the binding of osthole to HSA could induce partial changes in the second structure of the protein.