SPR传感检测抗体结合蛋白与IgG相互作用的研究

The kinetic study on the interactions of IgG and antibody-binding proteins based on SPR sensor

将自研的基于波长扫描的表面等离子体共振传感系统与动力学分析方法相结合,研究葡萄球菌蛋白A、链球菌蛋白G与免疫球蛋白G(immunoglobulin G,IgG)的相互作用关系.实验测得,蛋白A和蛋白G与IgG的结合速率常数分别为1.3×10^5 L·mol^-1·s^-1和5.0×10^4 L·mol^-1·s^-1,说明蛋白A与IgG的结合效率更高.同时测得蛋白A和蛋白G与IgG的解离速率常数分别为2.1×10^-2 s^-1和5.0×10^-3 s^-1,说明蛋白G与IgG形成的复合物更稳定.此外,由解离速率常数与结合速率常数的比值得出蛋白G对IgG的亲和力较大.实验结果可为优化抗体固定方法提供必要参考和理论支撑.

We study the interactions between staphylococal protein A or streptococcus protein G and immunoglobulin IgG,respectively,based on the self-developed wavelength-based surface plasmon resonance(SPR)sensing system combined with the kinetic analysis.The experimental results show that the association rate constants k a of protein A and protein G with IgG are 1.3×10^5 L·mol^-1·s^-1 and 5.0×10^4 L·mol^-1·s^-1,indicating that the protein A binds to IgG more efficiently.At the same time,the dissociation rate constants k d of protein A and protein G from IgG are detected to be 2.1×10^-2 s^-1 and 5.0×10^-3 s^-1,indicating that the complex formed by protein G and IgG is more stable.In addition,the ratio of k d to k a indicates that protein G has higher affinity for IgG.This study may provide necessary reference and important theoretical support for the optimization of antibody immobilization methods.