Flow cytometric analysis of 293 cells transiently expressing mutant GPIIb-IIIa.

WT, wild-type GPIIb-IIIa; KO, GPIIb-IIIa having 2 amino acid insertion between 160-161 of GPIIb; CAM, GPIIb-IIIa having D119→Y in GPIIIa; D163A, GPIIb-IIIa having D163→A in GPIIb; and T562N, GPIIb-IIIa having T562→N in GPIIIa. Cells were incubated with 10 μg/mL following mAbs: AP2, specific for GPIIb-IIIa complex; AP3, specific for GPIIIa; TP80, specific for GPIIb; OP-G2, activation-independent ligand-mimetic mAb to GPIIb-IIIa. Bound antibodies were detected by FITC-labeled goat anti–mouse immunoglobulin. The binding of PAC-1 (activation-dependent ligand mimetic mAb to GPIIb-IIIa) was examined in the presence of 10 μg/mL PT25-2 and detected by FITC-labeled goat anti–mouse IgM. MOPC21 (mouse myeloma IgG1) was used as a control antibody.