Figure 4. Plots of relative velocity versus different Mg²⁺ concentration for the wild-type and variant of EphA2, PKA and p38MAPK.

Each experiment was performed in triplicate (the error bar represents standard deviation). (a) The velocities of the wild-type (black) and Arg762Ala variant (red) of EphA2 are normalized to the velocities attained at 2 mM of Mg²⁺. (b) The velocities of the wild-type (black) and Lys189Ala variant (red) of PKA are normalized to the velocities attained at 2 mM of Mg²⁺. (c) The velocities of the wild-type (black) and Arg173Ala variant (red) of p38MAPK are normalized to the velocities attained at 2 mM of Mg²⁺.