Flow cytometric analysis of the binding of the activation-dependent fibrinogen-mimetic antibodies to the surface-expressed GPIIb-Ala5IIIa or GPIIb-Ala435IIIa.

(A) The binding of the activation-dependent fibrinogen-mimetic antibody Pl-55. Flow cytometric analysis was performed as described in “Materials and methods.” Note the very low binding of Pl-55 to CHO cells expressing WT GPIIb-IIIa (left) and the high binding to CHO cells expressing either GPIIb-Ala5IIIa or GPIIb-Ala435IIIa. (B) The binding of the activation-dependent fibrinogen-mimetic antibody PAC-1. Flow cytometric analysis was performed in the presence of 2.0 mM RGEW (upper) or RGDW (lower). Normal mouse IgM (NMIgM) and FITC-conjugated goat-anti-mouse IgM were used as the negative control and the secondary antibody, respectively.