双子表面活性剂溶液中大黄蒽醌类化合物与牛血清白蛋白的相互作用

On the Interaction of Rhubarb Authraquinone Analogues with Bovine Serum Albumin in Gemini Surfactant Solutions

在双子表面活性剂胶束模拟生物膜的介质中,采用荧光光谱法和紫外光谱法研究了大黄蒽醌类化合物(RAA)与牛血清白蛋白(BSA)的相互作用。结果表明,胶束-RAA二元配合物对BSA的内源性荧光较RAA单体有更强的荧光猝灭作用,其荧光猝灭机理为静态猝灭为主。以Lineweaver-Burk方程拟合得到了大黄素、大黄酸、芦荟大黄素三种大黄蒽醌类化合物与BSA作用的结合点位数、结合常数和热力学参数,其作用力主要为静电力和氢键。依据F?rster非辐射能量转移理论,计算出三种大黄蒽醌类化合物在BSA中与色氨酸残基间的结合距离皆小于7 nm,RAA与BSA之间能量转移使BSA荧光发生猝灭,并且胶束体积越大,R0及r值越大,即R0(H2O)<R0(C12-C4-C12)<R0(C16-C6-C16)。

The interaction of rhubarb authraquinone analogues(RAA)with bovine serum albumin(BSA)is investigated by fluorescence method and ultraviolet spectroscopy in the medium of biomembrane simulated by gemini surfactant micelles.The results show that the micelle-RAA binary complex has stronger fluorescence quenching effect on BSA than RAA monomer,and its fluorescence quenching mechanism is mainly static quenching.The numbers of binding point,binding constant and thermodynamic parameters between emodin,rhein,aloeemodin and BSA are obtained by LineweaverBurk equation.The thermodynamic parameters shows that the main force is electrostatic action and hydrogen bond in water or micelle solution.According to F?rster non-radiative energy transfer theory,the distance between the binding sites of RAA in BSA residues is less than 7 nm.The fluorescence of BSA is quenched by energy transfer between RAA and BSA.The larger the micelle volume is,the greater the R0 and r values are,namely as R0(H2O)<(R0C12-C4-C12)<R0(C16-C6-C16).