Figure 3.

Binding of fibrinogen and PAC-1 to normal or mutant αIIbβ3 expressed in CHO cells. (A) CHO cells stably expressing wild type or mutant αIIbβ3-P718 were preincubated in the absence or presence of 1 mM RGDS or 25 mM DTT for 5 min at room temperature. Cells were then incubated with FITC-PAC-1 for 30 min, washed, and analyzed by flow cytometry. (B) CHO cells were first labeled with anti-αIIb monoclonal antibody and then incubated with FITC-Fg in the absence or presence of thrombin as described in the Design and Methods section. (C) Soluble fibrinogen-dependent aggregation of CHO cell transfectants. Non-transfected cells (CHO) or αIIbβ3 expressing cells were incubated in serum-free medium containing 1 mg/mL fibrinogen in the absence or presence of 15 mM DTT. Aggregates were examined with a phase contrast microscope using a x4 objective. All the results are representative of, at least, three separate experiments.