光谱法研究盐酸小檗碱与牛血清白蛋白相互作用(英文)

采用荧光、同步荧光及紫外-可见光谱法研究溶液中盐酸小檗碱(BC)与牛血清白蛋白(BSA)的相互作用.结果表明:BC对BSA荧光有较强的猝灭作用,其猝灭机理为以静态猝灭为主并结合一定动态猝灭的复合过程.利用荧光猝灭反应求得BC与BSA之间的结合常数和结合位点数.根据F rster非辐射能量转移理论,计算得到BC与BSA之间的结合距离小于8nm,表明二者之间能够发生能量转移.根据反应热力学参数确定二者的相互作用是一个自发的过程,且静电力是它们之间相互作用的主要作用力类型.采用同步荧光考察BC对BSA构象的影响,随着BC浓度的增大,色氨酸残基所处环境的疏水性改变,从而导致BSA的构象发生变化.

Spectroscopic Investigation of Interaction between Berberine Chloride and Bovine Serum Albumin

The interaction between berberine chloride (BC) and bovine serum albumin (BSA) in aqueous solution was investigated by means of fluorescence,synchronous fluorescence and UV-Vis spectra.The fluorescence of BSA was quenched remarkably by BC and the quenching mechanism was deemed as mainly static quenching,accompanying with dynamic quenching at the same time.The binding constants K and the number of binding sites n were calculated at different temperatures by fluorescence quenching method.The BC-BSA binding distance was determined to be less than 8 nm according to Frster non-radioactive resonance energy transfer theory,and suggested that the energy transfer occured from BSA to BC.Based on the obtained thermodynamic parameters,the interaction process was spontaneous and the electrostatic forces played a major role in the process.In addition,the effect of BC on the conformation of BSA was analyzed by using synchronous fluorescence spectra.The alterative configuration of BSA was induced by the hydrophobic environment of tryptophan residues with increasing the BC concentration.