测量血小板膜糖蛋白与血管性血友病因子黏附解离力

Determination of the Detachment Force of Platelet Membrane Protein GPIb/IX and von Willebrand Factor

本实验用微吸管技术研究血管性血友病因子(von Willebrand factor,VWF)与血小板膜糖蛋白(GPIb/IX)之间相互识别、黏附的反应率及两种蛋白黏附之后发生解离时所需要的解离力。利用经过转染可表达人血小板膜糖蛋白GPIb/IX的CHO细胞与包被有VWF的兔红细胞互相接触并施加一定的外界压力,保持压力一段时间之后根据分开两细胞时红细胞变形判断蛋白质识别与否,记录两种蛋白质发生识别黏附的几率。通过对细胞变形的测量和数据处理得出GPIb/IX与VWF识别后的解离力。携带GPIb/IX或VWF的细胞对心挤压0.5μm,持续30s的实验状态下,两个细胞间发生黏附的概率约为15.0%。通过对红细胞形变的分析,得到携带GPIb/IX或VWF的细胞发生黏附后的解离力呈随机分布状态。分布的峰值,即解离力的最大几率值为10 pN。

CHO cells expressing human GPIb/IX and rabbit red blood cells coated with human yon Willebrand factor（ VWF） were adapted to our study on the binding probability and the detachment force of GPIb/IX and VWF. With the micropipette system, the two cells were impinged under a constant force for controlled time. When the cells were pulled apart, the deformation of RBC was recorded, and the binding score and detachment force of the proteins were determined. After the two cells were impinged into 0.5 btm for 30 s, the binding probability of the two cells carrying GPIb/IX and VWF was 15.0%. Via analyzing the deformation of red blood cells, we found out the distribution of rupture forces of cells with GPIb/IX and VWF. Therefore, we infer that the continuous distribution of the detachment force is due to the stochastic effect. The most probable value of the detachment force was 10 pN.