Table 1.

Initial rates of wild-type or PT6 prothrombin by FXa with varying components of prothrombinase.

	Wild-type		PT6
	Rate	Fold	Rate	Fold	p
	s − 1		s − 1
FXa	3.9 ± 4.3 × 10−4	1	5.1 ± 5.8 × 10−4	1	0.08
FXa, PCPS	1.8 ± 0.5 × 10−2	44.9	1.4 ± 0.1 × 10−2	27.3	0.29
FXa, FVa	1.8 ± 0.5 × 10−2	46.9	5.3 ± 3.7 × 10−3	10.4	<0.005
FXa, PCPS, FVa	66.6 ± 9.6	1.7 × 105	55.1 ± 8.7	1.1 × 105	<0.05

Wild-type or PT6 was activated by prothrombinase, FXa/FVa, FXa/PCPS, or FXa alone (see methods for concentrations). All reactions contain 5 mM CaCl₂. Fold differences in initial rates are calculated separately for wild-type and PT6, relative to activation by FXa alone. Statistical significance was measured between wild-type and PT6 for each set of experiments using Student’s t-test. Values represent mean ± SD of at least two separate experiments in duplicates.