Figure 8.

Effect of receptor clustering on reversible and irreversible ligand binding to α_IIb(FKBP)₂β₃. Binding of PAC1 in response to anti–LIBS6 Fab was initiated in CHO cells stably- expressing α_IIb(FKBP)₂β3, either in the absence or presence of AP1510. After 10 or 30 min, half of each sample was treated with 5 mM EDTA to displace reversibly bound PAC1 and half was not. Then specific PAC1 binding was determined. Reversible PAC1 binding was defined as specific binding displaced by EDTA, and irreversible binding was defined as specific binding that was not displaced by EDTA. Data represent the means ± SEM of three experiments.