牛蒡苷与人血清白蛋白的相互作用

The Interaction between Arctiin of Active Constituent of Medical Plant and Human Serum Albumin

运用荧光光谱法和紫外吸收光谱法研究了牛蒡苷与人血清白蛋白(HSA)的相互作用。结果显示,随着牛蒡苷浓度的增大,HSA的荧光强度明显增强并且发生蓝移;逐渐增大的各向异性值表明,牛蒡苷能够嵌插到HSA的疏水空腔中;求得25,32,39℃时牛蒡苷与HSA反应的结合常数分别为1.04×105,9.78×104和9.58×104L/mol;热力学参数(ΔH=-4.63kJ/mol,ΔS=80.48J/mol·K),表明维持药物与蛋白质的相互作用力主要是静电作用力。

The interaction of arctiin with human serum albumin （HSA） was investigated by fluorescence and UV/vis absorption spectra under the simulated physiological conditions. The experimental results showed that the fluorescence intensity of HSA could be highly enhanced accompanied with hypsochromic shift with the addition of arctiin. The fluorescence anisotropy （r） of arctiin was increased when HSA was added, this result suggested that the drug is located in a restricted environment in HSA. The binding constants at 25, 32, 39 ℃were calculated to be 1.04 ×10^5, 9.78 ×10^4, 9.58×10^4 L/mol, respectively. The thermodynamic parameters obtained （△H： -4.63 kJ/mol, AS： 80.48 J/mol-1·K-1） implied that electrostatic interaction should be the predominant intermolecular forces stabilizing the complex.