Metal Preferences of Zinc-Binding Motif on Metalloproteases

Table 2

Kinetic parameters for the hydrolysis of Arg-Arg-NA, zinc contents, and zinc dissociation constants of wild-type and mutated rat DPP IIIs.

Enzymes	𝑘cat/𝐾𝑀×10^−4; (M^-1 s^-1)	Zinc content (mol/mol of protein^a)	Zinc dissociation constant (M) (𝐾𝑑)
Wild-type	73.6±6.9	1.02±0.15	(4.5±0.1)×10^−13
E507D	22.8±1.9	0.65±0.07	(1.0±0.2)×10^−11
E507A	4.43±0.41	0.29±0.04	(1.0±0.2)×10^−8
E512D	21.0±0.19	0.45±0.06	(1.4±0.1)×10^−12
E512A	2.45±0.28	0.08±0.01	(2.6±0.7)×10^−9

^aValues are means ± SD of two separately prepared enzymes with duplicate determinations.