. 2011 Oct 5;286(49):41949–41962. doi: 10.1074/jbc.M111.301218

TABLE 3.

The kinetic parameters and stoichiometry of inhibition for the reaction of sctPA, tctPA, and tcuPA with NBD P9 PAI-1 and its Vn complexes in the presence of dsDNA

k_lim and K_m were calculated by fitting an equation k_obs = k_lim [E]/(K_m + [E]) to plots of k_obs versus [E] using SigmaPlot 11.0 (SPSS, Inc.) as described under “Experimental Procedures.” The stoichiometry of inhibition (SI), the number of moles of PAI-1 required to inhibit 1 mol of the enzyme, was estimated from the results of a gradient SDS-PAGE of the products of the reaction of recombinant WT PAI-1 and its complexes with Vn with the proteinase with or without dsDNA (10 μg/ml).

Enzyme	dsDNA				Vn				dsDNA + Vn
Enzyme	k_lim	K_m	k_lim/K_m	SI	k_lim	K_m	k_lim/K_m	SI	k_lim	K_m	k_lim/K_m	SI
	s⁻¹	nm	μm⁻¹s⁻¹		s⁻¹	nm	μm⁻¹s⁻¹		s⁻¹	nm	μm⁻¹s⁻¹
tctPA	0.87 ± 0.03	16 ± 4	54.4	1.1 ± 0.2	0.54 ± 0.04	34 ± 6	15.9	1.0 ± 0.1	1.04 ± 0.04	4 ± 3	260	1.1 ± 0.1
sctPA	0.70 ± 0.04	60 ± 10	11.7	1.0 ± 0.1	0.86 ± 0.05	300 ± 20	2.9	1.0 ± 0.1	0.68 ± 0.03	10 ± 4	68	1.1 ± 0.2
tcuPA	15.2 ± 0.6	70 ± 10	218	1.2 ± 0.1	13.0 ± 0.2	300 ± 30	43.3	1.1 ± 0.2	8.6 ± 0.2	30 ± 5	280	1.2 ± 0.2