小檗碱与人血清白蛋白结合的电喷雾离子阱质谱研究

Studies on the Non-covalent Binding Between Berberine and Human Serum Albumin by Electrospray Ion Trap Mass Spectrometry

以小檗碱与人血清白蛋白间的非共价结合作用为例,提出了一种应用电喷雾离子阱质谱(ESI-ITMS)研究蛋白-配体非共价结合稳定常数与结合计量比等特性的新方法。根据小檗碱与人血清白蛋白间的ESI-ITMS滴定实验结果,小檗碱与人血清白蛋白形成复合物的最大表观化学结合计量比为4.4∶1;根据ESI-ITMS滴定实验结果的Scatchard方程分析,小檗碱-人血清白蛋白复合物的表观稳定常数K值为1.29×105L/mol,结合位点数n为5.1;根据作用温度对复合物热力学常数△H、△S的影响,确定小檗碱与人血清白蛋白间的作用力主要为疏水作用力。实验结果与应用荧光法得到的结果基本一致。

A new mass spectrometric method stoichiometry of protein-ligand interaction was for determining association constants and binding presented in this paper based on electrospray ion trap mass spectrometry （ESI-ITMS） and titration method using the non-covalent binding between berberine and human serum albumin （HSA） as a study case. Based on the ESI-ITMS titration results and the influence of reaction temperature on the thermodynamic parameters AH, AS of the complexes, the maximum stoichiometric ratio of the complexes is 4. 4： 1 for BER-HSA and the main sort of binding force between berberine and HSA is hydrophobic forces. According to the ESI-ITMS titration Scatchard plot analysis, the binding constants （K） of the complex is 1.29× 10^5 L/tool and the binding sites（n） is 5.1.