Figure 2.

Dependence of k_obs values on ZPI concentration with fXa derivatives in the presence of PZ. The k_obs values for the ZPI inhibition of fXa (○), fXa-des-EGF-1 ([unk]) and fXa/PC-Gla (…) (0.5 nM each) were determined in the presence of PZ (50-150 nM) and varying concentration of ZPI (10-80 nM) on PC/PS vesicles (25 μM) in TBS containing 0.1 mg/mL BSA, 0.1% PEG 8000 and 5 mM Ca²⁺ at room temperature by an amidolytic activity assay described under “Experimental Procedures”. The k₂ values were calculated from the slopes of the straight lines and presented in Table 1. Data are derived from averages of at least 3 independent measurements.