FIGURE 6.
Activation of prothrombin. Reaction mixtures containing 1.4 μm prothrombin and 50 μm PCPS were incubated at 25 °C in the absence (A) or in the presence (B) of 20 nm FVa and initiated with FXa 0.1 nm (wild-type rFXa) or 0.4 nm (mutant rFXa). Aliquots of the reaction mixture were quenched during the initial rate of the reaction (0, 0.5, 1, 1.5, and 2.0 min), and thrombin generation was determined by using the chromogenic substrate S-2238. ▪, PDFXa; ○, rFXa; ▴, rFXaI16L; and ⋄, rFXaV17A. The data are representative of two to three similar experiments.