Effects of Inositol Phosphate Analogs upon PPIP5K2KD Activities: ATPase, 1,5-[PP]2-InsP4 Dephosphorylation and InsP6 Phosphorylation
(A and B) Dose-response curves are shown for the indicated inositol phosphate analogs and their stimulation of ATPase activities (A), and their inhibition of ADP-driven dephosphorylation of 100 nM [PP]2-InsP4 (B). Error bars represent SEs (n = 3). The EC50 and IC50 values for the molecules tested are given in the key to the right of (A) and (B).
(C) A Dixon plot of the inhibition of InsP6 kinase activity of PPIP5K2KD by 2,5-di-O-Bn-InsP4 (10); the data are from a representative experiment (one of three), performed in duplicate. Insets illustrate the reaction being assayed.