TABLE 5.

Steady-state kinetic parameters for microplasminogen activation by equimolar complexes of SK/SK γ domain mutants and HPN

The kinetic parameters for substrate μPG activation were determined at 22 °C with the chromogenic substrate in 50 mm Tris-Cl buffer, pH 7.5, 100 mm NaCl as described under “Experimental Procedures.” The data represent the mean of three independent determinations.

Activator species	Km	kcat	kcat/Km
	μm	min−1	min−1μm−1
wtSK	1.2 ± 0.1	0.13	0.1
SK-D328G	1.2 ± 0.4	0.01	0.008
SK-K334E	1.4 ± 0.3	0.04	0.02
SK-G344D	1.2 ± 0.2	0.02	0.016