. Author manuscript; available in PMC: 2014 Jan 8.

Published in final edited form as: Biochemistry. 2012 Dec 27;52(1):143–151. doi: 10.1021/bi301239z

Table 2.

Apparent Dissociation Constants for Interactions of Wild-Type and R165A Mutant FXa with FVa

FXa, nM	K_d,app FXa-FVa, nM
FXa, nM	Wild Type FXa	Mutant (R165A) FX_a
5	2.2 ± 0.6	58 ± 7
20	20 ± 4.2	92 ± 12
50	43 ± 13.3	128 ± 27

	K_d^dimer, nM
	Wild Type FXa	Mutant (R165A) FX_a
	16 ± 4	147 ± 25

Dissociation constants obtained from the data plotted in Figure 1B and from similar experiments with R165A rHFXa show that the R165A mutation in FXa inhibits both the interaction with FVa and FXa dimer formation. The value of $K_{d}^{X a_{2}}$ was obtained from fitting the data in the figure. We previously reported a value of 14 ± 1 nM obtained from more extensive sets of data in the absence of FVa (13).