TABLE 4.

Kinetic parameters for hydrolysis of substrates containing juxtamembrane region of TNFα and α-helix-inducing heptads by ADAM10, 12, and 17

The results are reported as averages ± standard deviation (n = 3).CDD, catalytic domain + disintegrin domain.

Enzyme	kcat/Km			kcat			Km
	Substrate 6	Substrate 8	Substrate 9	Substrate 6	Substrate 8	Substrate 9	Substrate 6	Substrate 8	Substrate 9
	m−1 s−1			s−1			μm
ADAM17 ECD	1.5 ± 0.25 × 104	0.9 ± 0.04 × 104	0.16 ± 0.08 × 104	0.34 ± 0.03	0.064 ± 0.01	0.003 ± 0.001	24 ± 6.2	7.5 ± 1.3	2.0 ± 0.1
ADAM17 CD	0.62 ± 0.08 × 104	0.9 ± 0.04 × 104	0.16 ± 0.00 × 104	0.12 ± 0.03	0.07 ± 0.01	0.004 ± 0.001	20 ± 0.2	7.9 ± 0.4	2.3 ± 0.6
ADAM10 ECD	0.5 ± 0.04 × 104	0.39 ± 0.006 × 104	0.06 ± 0.00 × 104	0.06 ± 0.01	0.03 ± 0.004	0.004 ± 0.001	13 ± 0.5	6.2 ± 0.7	5.5 ± 1.5
ADAM12 CDD	0.03 ± 0.001 × 104	0.05 ± 0.004 × 104	ND	0.006 ± 0.01	0.003 ± 0.002	ND	18 ± 5	6.2 ± 1.6	ND