分子模拟技术与光谱法结合研究硫酸沙丁胺醇与两种蛋白质的相互作用

Studies of Interaction Between Salbutamol Sulfate and Two Proteins by Molecular Modeling and Spectroscopic Methods

摘要:

目的: 研究了硫酸沙丁胺醇(salbutamol sulfate, SAS)与人血清白蛋白(human serum albumin, HSA)及人免疫球蛋白G(human Immunoglobulin G, HIgG)之间的相互作用. 方法: 在模拟生理条件下,采用分子模拟技术、紫外-可见吸收光谱法及圆二色谱法获得了HSA和HIgG结构改变的定性和定量依据. 结果: 根据分子对接技术所得数据可知:SAS与HSA之间的作用力主要是氢键、范德华力和静电作用;SAS与HIgG 之间的作用力主要有氢键、π-正电荷相互作用和范德华力.紫外-可见吸收光谱实验结果表明当SAS加入到HSA和HIgG溶液中时,HSA和HIgG的二级结构会发生变化,并且SAS与HSA和HIgG之间的淬灭机制为静态淬灭;由圆二色谱所得到的定量数据可知SAS的加入使得HSA的α螺旋结构由47.92%减小到46.53%.与此同时,SAS的加入使得HIgG的二级结构产生变化. 结论: 分子模拟技术、紫外-可见吸收光谱法及圆二色谱法结合适合于研究SAS与HSA和HIgG之间的相互作用,具有简单快速,灵敏度高等优点.

Abstract:

Objective: To study the interaction of salbutamol sulfate (SAS) with human serum albumin (HSA) and human immunoglobulin G (HIgG). Method: Qualitative and quantitative structure changes of HSA and HIgG were performed by molecular modeling, UV-visible absorbance and circular dichroism spectroscopy methods. Result: The experiment results obtained from molecular modeling indicated that there were hydrogen bonds, Van der Waals force and electrostatic interactions between SAS and HSA;meanwhile, hydrogen bonds, π-cation interaction and Van der Waals force played the major role in the interaction of SAS and HIgG. Experimental results observed from UV-visible absorbance spectroscopy showed that the secondary structures of HSA and HIgG were altered in the presence of salbutamol sulfate, and their quenching mechanisms were both suggested as static quenching. Moreover, the α-helices of HSA in the presence of SAS were decreased from 47.92% to 46.53 %, and the secondary structure of HIgG was also changed because of the addition of salbutamol sulfate, which were obtained from the circular dichroism spectroscopy. Conclusion: Molecular modeling, UV-visible absorbance and circular dichroism spectroscopy are good methods for investigating the interaction between SAS, HSA and HIgG. They have the advantages of high speed and high sensitivity.