基于荧光光谱的硫酸阿托品拮抗中乌头碱毒性的机制研究

目的 研究模拟生理条件下中乌头碱（MA）与牛血清白蛋白（BSA）的键合作用，以及硫酸阿托品（AS）对其相互作用的影响。方法 主要采用荧光光谱法及紫外吸收光谱法进行研究。结果 MA对BSA有较强的荧光猝灭作用，猝灭机制为动态猝灭。MA与BSA表观结合常数（K_b）和结合位点数（n）均随着温度升高而增大，二者之间的相互作用力类型主要为疏水作用，结合距离为4.44 nm，该反应是自发进行的。同步荧光光谱图的信息表明MA对蛋白微环境有影响。AS使MA和BSA的K_b和n均减小；抑制MA对BSA构象的改变。结论 MA与BSA能发生相互作用，AS与MA间存在竞争作用，能够增加游离型MA浓度，通过减少MA在生物体内的积累，加快代谢，发挥解毒作用。

Atropine sulfate against toxicity of mesaconitine by fluorescence spectra

Objective To study the bonding of mesaconitine (MA) with bovine serum albumin (BSA) and the effect of atropine sulfate (AS) on its interaction. Methods Ultraviolet absorption and fluorescence spectra were used. Results MA had strong fluorescence quenching effect on BSA via a dynamic quenching procedure. The apparent bonding constant (K_b) and the number of bonding sites (n) of MA and BSA were increased with temperature rising. The predominant intermolecular forces between MA and BSA were hydrophobic interactions, which could make the MA-BSA bonding stabilized and the combined distance was 4.44 nm. The negative value of free energy change was taken as an evidence for the spontaneity of MA-BSA bonding. The synchronous fluorescence spectra indicated that protein microenvironment was changed by MA. AS decreased K_b and n, and inhibited the conformation change of BSA. Conclusion AS could act competitively with MA in bonding to BSA and increase the content of free MA. AS could accelerate the metabolism for detoxification by reducing accumulation in body.