Figure 7. Kinetic analysis of partially purified PfPDE1.

(A) Michaelis–Menten kinetics of PfPDE1. Partially purified PfPDE1 protein was prepared as described in the Experimental section. PfPDE1 was assayed at various cGMP concentrations (0.03125–4 μM). (B) Lineweaver–Burk plots of the same sets of data are shown. The data are expressed as the means±S.E.M. for three independent experiments. K_m and V_max values are expressed as the means±S.E.M. for triplicate assays. The bivalent cation used was 1 mM MnCl₂.