Study of Interaction Force between Antigen and Antibody Using Flow Chamber Method

A parallel plate flow chamber was used to study the interaction force between human IgG (immobilized on a chip surface as ligand) and goat anti-human IgG (immobilized on microspheres surface as receptor). First, it was demonstrated that the binding force between the microspheres and the chip surface came from the bio-specific interaction between the antigen and the antibody. Secondly, it was obtained that the critical shear rate to detach microspheres from the chip surface increases with the ligand surface concentration. Finally, two models to estimate the antigen-antibody bond strength considering bonds' positions were proposed and analyzed.

受体-配体键二维正反应率的直接实验测定

<正>细胞粘附分子间相互作用介导了炎症反应、肿瘤转移、动脉硬化和创伤愈合等重要生物学过程,定量描述为受体-配体结合和解离的二维反应动力学。反应动力学参数——分子结合时的正反应率和解离时的负反应率——决定着分子反应发生的可能性、快慢和键的强弱,故反应动力学参数的测量是理解生理现象本质的关键。现有定量测量技术包括微吸管、原子力显微镜、微悬臂梁等等,均是从键的解离过程出发,计算粘附频率、拟合得到正/负反应率。对于二维正反应率的测量而言,均为间接方法。比如,Rinko首次从解离过程所得到的键断裂力及键寿命分布估算得到了选择素(selectin)-配体键的二维正反应率为1.7μm~2/s。但二维正反应率的直接实验测定目前无相关报道,其实现的难点在于很难直接观察到分子结合的过程。