目的揭示"靶心"型细胞接触面荧光恢复实验中黏附分子扩散-反应动力学机制,发展一种利用荧光恢复实验测量二维反应动力学速率与扩散系数的新方法。方法建立"靶心"型细胞接触面荧光恢复实验的黏附分子扩散-反应偶联数学模型,数值模拟接触面荧光恢复的物理过程,分析荧光恢复的参数依赖特性。结果荧光恢复的起始阶段,在靶环区域内先将经历一个与反应无关的自由配体扩散过程,尔后,细胞接触面内的荧光恢复,将从分子扩散为主导逐步过渡到反应为主导的过程;细胞接触面荧光恢复的时间历程曲线,与二维反应动力学速率与扩散系数密切相关。结论本文提出的"靶心"型细胞接触面荧光恢复实验数学模型不但可以预报荧光恢复的物理过程,而且可以用来发展一种测量二维反应动力学速率与扩散系数的新技术。

Objective To reveal the reaction dynamic mechanism of the adhesive molecules being involved in the fluorescence recovery after photo-bleaching (FRAP) experiment of the "bull’s eye" type’s contact area, and to develop a new method to measure 2D kinetic rates of the adhesion molecules and their retarded diffusion by FRAP experiment. Method For the FRAP experiment of the "bull’s eye" type’s contact area, a coupled diffusion-reaction model of two different adhesive molecular systems is presented firstly, then the physical process of the FRAP is revealed by numerical modeling, and the behavior of the reaction rate and diffusive retarded coefficient in the FRAP is shown by analyzing the numerical results. Results The FRAP of the "bull’s eye" type’s contact area are governed not only by the 2D reaction rate but also by the diffusive retarded coefficient of the adhesive molecules; Firstly, the process of the FRAP is a free molecular diffusive in the edge domain of the "bull’s eye", then the effect of the reaction is more and more significant as time flows, and become a dominant factor. Conclusion The FRAP experiment of the "bull’s eye" type’s contact area can be modeled by our mathematical model, which can also be used to developed a new technique to measure 2D kinetic rates of the adhesion molecules and their retarded diffusion in a stable "bull’s eye" type’s contact area.

国家自然科学基金(10372118);广东省自然科学基金(04009767);教育部回国留学人员科研启动基金