Fig. 2.

Concentration-dependence of GD-PC activation by thrombin. (Top) Concentration dependence of wild-type GD-PC activation by thrombin (1 nM) was monitored in the absence (○) or presence (•) of TM456 in TBS/Ca²⁺ as described in Methods.(Middle) The same as above except that the activation of Cys-67–82 protein C by thrombin was measured in the absence (○) or presence (•) of TM456. (Bottom) The same as above except that the activation of Cys-67–82 protein C by R35E thrombin was measured in the presence of TM456 in TBS/Ca²⁺ (•) or without TM456 in TBS/Ca²⁺ (○) and TBS/EDTA (□). Solid lines are best fit of kinetic data to the Michaelis-Menten equation. The apparent K_m and k_cat values are presented in Table 1.