Figure 11.

Substrate Affinity of the FRA3 Phosphatase.

The kinetic activity of FRA3 phosphatase was assayed in the presence of various concentrations of substrates. The results were analyzed by Lineweaver-Burk plots to determine the K_m and V_max values.

(A) The kinetic property of FRA3 toward PtdIns(4,5)P₂. PtdIns(4,5)P₂ (6 to 400 μM) was incubated with 0.25 μg of recombinant FRA3 protein.

(B) The kinetic property of FRA3 toward PtdIns(3,4,5)P₃. PtdIns(3,4,5)P₃ (6 to 400 μM) was incubated with 0.5 μg of recombinant FRA3 protein.

(C) The kinetic property of FRA3 toward Ins(1,4,5)P₃. Ins(1,4,5)P₃ (50 to 800 μM) was incubated with 0.5 μg of recombinant FRA3 protein.