FITC-fibrinogen binding to CHO cells expressing IIb^P145Aβ3.

Untransfected CHO cells and CHO cells expressing comparable levels of either wild-type αIIbβ3 or mutant αIIb^P145Aβ3 were incubated with 200 μg/mL FITC-fibrinogen in the absence or presence of the αIIbβ3-activating β3-specific monoclonal antibody PT25-2. The amount of FITC-fibrinogen bound was then determined by flow cytometry. Reduction of fibrinogen binding to baseline levels by 1 mM RGDS and 1 mM EDTA indicates that the binding was αIIbβ3-specific. The gray bar indicates the location of the mean fluorescence intensity in the histograms of cells incubated with PT25-2.