Figure 5.

Binding of FXa to PS. A) Binding of FXa to Zn²⁺-containing PS (squares) or to Zn²⁺-deficient commercial PS (circles) immobilized on a plate at 2 μg/ml. Results were confirmed in 2 separate experiments, and results for Zn²⁺-containing PS confirm our earlier report (6). B) SPR binding experiments. See Materials and Methods for details. Peak binding from 5–6 sensograms obtained using different concentrations of FXa binding to Zn²⁺-containing PS (squares) or to commercial Zn²⁺-deficient PS (circles). Weak binding of prothrombin (FII, triangle) to Zn²⁺-containing PS is used as a control; consistent results for several higher concentrations of FII are not shown. Global fits of sensograms corresponding to these data are shown in Table 3.